Spring Maven project is not recognised in IntelliJ 2018.1

Do you have Maven plugin enabled in Settings(Preferences) | Plugins? Please attach screenshots, showing the problem (including the project structure which is created in project tool window) and idea.log after IDE restart and  reproducing.

here it is

2018-04-12 10:26:20,345 [ 65660] INFO - org.jetbrains.io.BuiltInServer - web server stopped
2018-04-12 10:26:22,951 [ 0] INFO - #com.intellij.idea.Main - ------------------------------------------------------ IDE STARTED ------------------------------------------------------
2018-04-12 10:26:23,149 [ 198] INFO - #com.intellij.idea.Main - IDE: IntelliJ IDEA (build #IU-181.4203.550, 26 Mar 2018 21:23)
2018-04-12 10:26:23,149 [ 198] INFO - #com.intellij.idea.Main - OS: Mac OS X (10.13.4, x86_64)
2018-04-12 10:26:23,149 [ 198] INFO - #com.intellij.idea.Main - JRE: 1.8.0_152-release-1136-b20 (JetBrains s.r.o)
2018-04-12 10:26:23,149 [ 198] INFO - #com.intellij.idea.Main - JVM: 25.152-b20 (OpenJDK 64-Bit Server VM)
2018-04-12 10:26:23,158 [ 207] INFO - #com.intellij.idea.Main - JVM Args: -Xms128m -Xmx750m -XX:ReservedCodeCacheSize=240m -XX:+UseCompressedOops -Dfile.encoding=UTF-8 -XX:+UseConcMarkSweepGC -XX:SoftRefLRUPolicyMSPerMB=50 -ea -Dsun.io.useCanonCaches=false -Djava.net.preferIPv4Stack=true -Dide.run.dashboard=true -XX:+HeapDumpOnOutOfMemoryError -XX:-OmitStackTraceInFastThrow -Xverify:none -XX:ErrorFile=/Users/marc/java_error_in_idea_%p.log -XX:HeapDumpPath=/Users/marc/java_error_in_idea.hprof -Xbootclasspath/a:../lib/boot.jar -Djb.vmOptionsFile=/Users/marc/Library/Preferences/IntelliJIdea2018.1/idea.vmoptions -Didea.java.redist=jdk-bundled -Didea.home.path=/Applications/IntelliJ IDEA 18.1.app/Contents -Didea.executable=idea -Didea.paths.selector=IntelliJIdea2018.1
2018-04-12 10:26:23,158 [ 207] INFO - #com.intellij.idea.Main - ext: /Applications/IntelliJ IDEA 18.1.app/Contents/jdk/Contents/Home/jre/lib/ext: [sunec.jar, nashorn.jar, cldrdata.jar, jfxrt.jar, dnsns.jar, localedata.jar, sunjce_provider.jar, meta-index, sunpkcs11.jar, jaccess.jar, zipfs.jar]
2018-04-12 10:26:23,158 [ 207] INFO - #com.intellij.idea.Main - ext: /System/Library/Java/Extensions: [MRJToolkit.jar]
2018-04-12 10:26:23,158 [ 207] INFO - #com.intellij.idea.Main - JNU charset: UTF-8
2018-04-12 10:26:23,174 [ 223] INFO - #com.intellij.idea.Main - JNA library (64-bit) loaded in 16 ms
2018-04-12 10:26:23,187 [ 236] INFO - #com.intellij.idea.Main - initializing environment
2018-04-12 10:26:23,188 [ 237] INFO - .intellij.util.EnvironmentUtil - loading shell env: /bin/bash -l -i -c '/Applications/IntelliJ IDEA 18.1.app/Contents/bin/printenv.py' '/private/var/folders/xc/z6sl1s9j4k5f5_pw7swbs46m0000gn/T/intellij-shell-env.tmp'
2018-04-12 10:26:23,198 [ 247] INFO - #com.intellij.util.ui.JBUI - User scale factor: 1.0
2018-04-12 10:26:23,198 [ 247] INFO - #com.intellij.util.ui.JBUI - System scale factor: 2.0 (JRE-managed HiDPI)
2018-04-12 10:26:23,301 [ 350] INFO - .intellij.util.EnvironmentUtil - shell environment loaded (21 vars)
2018-04-12 10:26:23,316 [ 365] INFO - .intellij.util.EnvironmentUtil - LC_CTYPE=en_US.UTF-8
2018-04-12 10:26:24,551 [ 1600] INFO - .intellij.idea.IdeaApplication - CPU cores: 8; ForkJoinPool.commonPool: java.util.concurrent.ForkJoinPool@348787fe[Running, parallelism = 7, size = 0, active = 0, running = 0, steals = 0, tasks = 0, submissions = 0]; factory: com.intellij.concurrency.IdeaForkJoinWorkerThreadFactory@67f125
2018-04-12 10:26:25,904 [ 2953] INFO - llij.ide.plugins.PluginManager - Plugin 'Lombok Plugin' can't be loaded because: Plugin since-build or until-build don't match this product's build number
2018-04-12 10:26:25,908 [ 2957] INFO - llij.ide.plugins.PluginManager - Plugin 'BashSupport' can't be loaded because: Plugin since-build or until-build don't match this product's build number
2018-04-12 10:26:25,909 [ 2958] INFO - llij.ide.plugins.PluginManager - Plugin 'Kotlin' can't be loaded because: Plugin since-build or until-build don't match this product's build number
2018-04-12 10:26:25,911 [ 2960] INFO - llij.ide.plugins.PluginManager - Plugin 'Docker integration' can't be loaded because: Plugin since-build or until-build don't match this product's build number
2018-04-12 10:26:25,913 [ 2962] INFO - llij.ide.plugins.PluginManager - Plugin 'Presentation Assistant' can't be loaded because: Plugin is disabled
2018-04-12 10:26:26,210 [ 3259] INFO - llij.ide.plugins.PluginManager - 145 plugins initialized in 1272 ms
2018-04-12 10:26:26,217 [ 3266] INFO - llij.ide.plugins.PluginManager - Loaded bundled plugins: ASP (0.1), Android Support (10.3.0), AngularJS (181.4203.550), Ant Support (1.0), Application Servers View (0.2.0), AspectJ Support (1.2), Bytecode Viewer (0.1), CFML Support (3.53), CSS Support (181.4203.550), CVS Integration (11), Cloud Foundry integration (1.0), CloudBees integration (1.0), CoffeeScript (181.4203.550), Copyright (8.1), Coverage (181.4203.550), Cucumber for Groovy (181.4203.550), Cucumber for Java (181.4203.550), DSM Analysis (1.0.0), Database Tools and SQL (181.4203.550), Eclipse Integration (3.0), EditorConfig (181.4203.550), Emma (181.4203.550), Flash/Flex Support (181.4203.550), FreeMarker support (1.0), GWT Support (1.0), Geronimo Integration (1.0), Gherkin (999.999), Git Integration (8.1), GitHub (181.4203.550), GlassFish Integration (1.0), Google App Engine Integration (1.1.4), Gradle (181.4203.550), Grails (9.0), Groovy (9.0), Guice (8.0), HTML Tools (2.0), HTTP Client (181.4203.550), Haml (181.4203.550), Heroku integration (181.4203.550), Hibernate Support (1.0), I18n for Java (181.4203.550), IDE Settings Sync (181.4203.550), IDEA CORE (181.4203.550), IntelliLang (8.0), J2ME (1.0), JBoss Arquillian Support (1.0), JBoss Drools Support (1.0), JBoss Frameworks Base Support (1.0), JBoss Integration (1.0), JBoss Seam Pageflow Support (1.0), JBoss Seam Pages Support (1.0), JBoss Seam Support (1.0), JBoss jBPM (2.0.0), JSR45 Integration (1.0), JUnit (1.0), Java Bytecode Decompiler (181.4203.550), Java EE: Batch Applications (1.0), Java EE: Bean Validation Support (1.1), Java EE: Contexts and Dependency Injection (1.1), Java EE: EJB, JPA, Servlets (1.0), Java EE: JMS, JSON Processing, Concurrency, Transaction (1.0), Java EE: Java Server Faces (2.2.X.), Java EE: RESTful Web Services (JAX-RS) (1.0), Java EE: Web Services (JAX-WS) (1.9), Java EE: WebSockets (1.0), Java Server Pages (JSP) Integration (1.0), Java Stream Debugger (181.4203.550), JavaFX (1.0), JavaScript Debugger (1.0), JavaScript Intention Power Pack (0.9.4), JavaScript Support (1.0), Jetty Integration (1.0), Less support (181.4203.550), Markdown support (181.4203.550), Maven Integration (181.4203.550), Maven Integration Extension (181.4203.550), Mercurial Integration (10.0), OpenShift integration (1.0), Osmorc (1.4.11), Perforce Integration (2.0), Persistence Frameworks Support (1.0), Playframework Support (1.0), Plugin DevKit (1.0), Properties Support (181.4203.550), QuirksMode (181.4203.550), Reactor framework support (1.0), Refactor-X (2.01), Remote Hosts Access (0.1), Resin Integration (8.1), SSH Remote Run (0.1), Sass support (181.4203.550), Settings Repository (181.4203.550), Smali Support (1.0), Spring AOP/@AspectJ (1.0), Spring Batch (1.0), Spring Boot (1.0), Spring Data (1.0), Spring Integration Patterns (1.0), Spring MVC (1.0), Spring OSGi (1.0), Spring Security (1.0), Spring Support (1.0), Spring Web Flow (1.0), Spring Web Services (1.0), Spring WebSocket (1.0), Spy-js (181.4203.550), Struts 1.x (2.0), Struts 2 (1.0), Stylus support (999.999), Subversion Integration (1.1), TFS Integration (999.999), Tapestry support (1.0), Task Management (1.0), Terminal (0.1), TestNG-J (8.0), Thymeleaf (1.0), Time Tracking (1.0), Tomcat and TomEE Integration (1.0), UI Designer (181.4203.550), UML Support (1.0), Vaadin Support (1.0), Velocity support (1.0), W3C Validators (2.0), WebLogic Integration (1.0), WebSphere Integration (1.0), XPathView + XSLT Support (4), XSLT-Debugger (1.4), YAML (181.4203.550), ZKM-Unscramble (1.0), dmServer Support (0.9.5), tslint (181.4203.550)
2018-04-12 10:26:26,217 [ 3266] INFO - llij.ide.plugins.PluginManager - Loaded custom plugins: .env files support (0.6), .ignore (2.4.0), AsciiDoc (0.20.2), CSV Plugin (1.5.1), PIT mutation testing Idea plugin (1.3.8), PlantUML integration (2.10.1), SonarLint (3.2.1.2406), Toml (0.2.0.12), Vaadin Designer 2 (2.2.3)
2018-04-12 10:26:26,217 [ 3266] INFO - llij.ide.plugins.PluginManager - Disabled plugins: BashSupport (1.6.13.173), Docker integration (173.3727.15), Kotlin (1.2.31-release-IJ2017.3-1), Lombok Plugin (0.16-2017.3.3), Presentation Assistant (0.9.10)
2018-04-12 10:26:27,161 [ 4210] INFO - cloudConfig.CloudConfigManager - === Start.updateConnection ===
2018-04-12 10:26:27,180 [ 4229] INFO - cloudConfig.CloudConfigManager - === Start: JBA_CONNECTED ===
2018-04-12 10:26:27,180 [ 4229] INFO - cloudConfig.CloudConfigManager - === doConnect ===
2018-04-12 10:26:27,180 [ 4229] INFO - cloudConfig.CloudConfigManager - === getConnectionState ===
2018-04-12 10:26:27,220 [ 4269] INFO - til.net.ssl.CertificateManager - Default SSL context initialized
2018-04-12 10:26:27,228 [ 4277] INFO - ellij.util.io.PagedFileStorage - lower=100; upper=500; buffer=10; max=705
2018-04-12 10:26:27,325 [ 4374] INFO - pl.local.NativeFileWatcherImpl - Starting file watcher: /Applications/IntelliJ IDEA 18.1.app/Contents/bin/fsnotifier
2018-04-12 10:26:27,337 [ 4386] INFO - pl.local.NativeFileWatcherImpl - Native file watcher is operational.
2018-04-12 10:26:27,492 [ 4541] INFO - .cloudConfig.CloudConfigClient - === Get cloud config URL: https://cloudconfig.jetbrains.com/cloudconfig/files ===
2018-04-12 10:26:27,862 [ 4911] INFO - com.intellij.ide.ui.UISettings - Loaded: fontSize=12, fontScale=1.0; restored: fontSize=12, fontScale=1.0
2018-04-12 10:26:27,950 [ 4999] WARN - nSystem.impl.ActionManagerImpl - keymap "Xcode" not found [Plugin: Git4Idea]
2018-04-12 10:26:27,974 [ 5023] WARN - nSystem.impl.ActionManagerImpl - keymap "Xcode" not found [Plugin: hg4idea]
2018-04-12 10:26:28,255 [ 5304] INFO - .openapi.application.Preloader - Finished preloading com.intellij.ide.ui.OptionsTopHitProvider$Activity@2223a310
2018-04-12 10:26:28,260 [ 5309] INFO - rains.ide.BuiltInServerManager - built-in server started, port 63342
2018-04-12 10:26:28,333 [ 5382] INFO - gs.impl.UpdateCheckerComponent - channel: release
2018-04-12 10:26:28,503 [ 5552] INFO - il.indexing.FileBasedIndexImpl - Index exts enumerated:128, number of extensions:69
2018-04-12 10:26:28,508 [ 5557] INFO - il.indexing.FileBasedIndexImpl - Index scheduled:5
2018-04-12 10:26:28,535 [ 5584] INFO - tellij.psi.stubs.StubIndexImpl - All stub exts enumerated:21, number of extensions:83
2018-04-12 10:26:28,536 [ 5585] INFO - tellij.psi.stubs.StubIndexImpl - stub exts update scheduled:0
2018-04-12 10:26:28,973 [ 6022] INFO - plication.impl.ApplicationImpl - 113 application components initialized in 4038ms
2018-04-12 10:26:29,083 [ 6132] INFO - .intellij.idea.IdeaApplication - App initialization took 6724 ms
2018-04-12 10:26:29,220 [ 6269] INFO - pl$FileIndexDataInitialization - Initialization done:712
2018-04-12 10:26:29,283 [ 6332] INFO - exImpl$StubIndexInitialization - Initialization done:62
2018-04-12 10:26:29,907 [ 6956] INFO - j.ide.plugins.RepositoryHelper - using cached plugin list (updated at 12/04/2018, 10:25)
2018-04-12 10:26:29,950 [ 6999] INFO - .openapi.application.Preloader - Finished preloading com.intellij.openapi.actionSystem.impl.ActionPreloader@8903c4f
2018-04-12 10:26:30,100 [ 7149] INFO - cloudConfig.CloudConfigManager - === End.connect ===
2018-04-12 10:26:30,224 [ 7273] INFO - com.intellij.ide.ui.UISettings - Loaded: fontSize=12, fontScale=1.0; restored: fontSize=12, fontScale=1.0
2018-04-12 10:26:30,532 [ 7581] INFO - j.ide.ui.OptionsTopHitProvider - 407 ms spent to cache options in application
2018-04-12 10:26:31,570 [ 8619] INFO - .openapi.application.Preloader - Finished preloading com.intellij.ide.ui.search.SearchableOptionPreloader@6fea4a31
2018-04-12 10:26:31,849 [ 8898] INFO - .openapi.application.Preloader - Finished preloading com.intellij.codeInsight.completion.CompletionPreloader@72f1e514
2018-04-12 10:26:31,853 [ 8902] INFO - .openapi.application.Preloader - Finished preloading com.intellij.ide.actions.GotoClassPresentationUpdater@488c2c3b
2018-04-12 10:26:35,335 [ 12384] INFO - ellij.project.impl.ProjectImpl - 24 project components initialized in 141 ms
2018-04-12 10:27:02,297 [ 39346] INFO - org.eclipse.jetty.util.log - Logging initialized @40376ms
2018-04-12 10:27:02,517 [ 39566] INFO - ellij.project.impl.ProjectImpl - 210 project components initialized in 651 ms
2018-04-12 10:27:02,518 [ 39567] INFO - le.impl.ModuleManagerComponent - 0 module(s) loaded in 0 ms
2018-04-12 10:27:02,957 [ 40006] INFO - j.ide.script.IdeStartupScripts - 0 startup script(s) found
2018-04-12 10:27:03,228 [ 40277] WARN - om.intellij.util.ProfilingUtil - Profiling agent is not enabled. Add -agentlib:yjpagent to idea.vmoptions if necessary to profile IDEA.
2018-04-12 10:27:03,515 [ 40564] INFO - CompilerBackwardReferenceIndex - backward reference index version differ due to: class java.io.FileNotFoundException
2018-04-12 10:27:03,883 [ 40932] INFO - ge.ExternalProjectsDataStorage - Loaded external projects data in 6 millis
2018-04-12 10:27:03,903 [ 40952] INFO - Tools.base.JsbtStartupActivity - Detecting buildfiles for com.intellij.lang.javascript.buildTools.grunt.GruntfileManager
2018-04-12 10:27:03,904 [ 40953] INFO - Tools.base.JsbtStartupActivity - Detecting buildfiles for com.intellij.lang.javascript.buildTools.gulp.GulpfileManager
2018-04-12 10:27:03,904 [ 40953] INFO - Tools.base.JsbtStartupActivity - Detecting buildfiles for com.intellij.lang.javascript.buildTools.npm.PackageJsonFileManager
2018-04-12 10:27:03,913 [ 40962] INFO - .diagnostic.PerformanceWatcher - Post-startup activities under progress took 102ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:04,883 [ 41932] INFO - .diagnostic.PerformanceWatcher - Pushing properties took 30ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:05,513 [ 42562] INFO - tartup.impl.StartupManagerImpl - /Users/marc/development/experiments/demo/.idea case-sensitivity: expected=false actual=false
2018-04-12 10:27:05,523 [ 42572] INFO - pl.projectlevelman.NewMappings - VCS Root: [] - [<Project>]
2018-04-12 10:27:05,701 [ 42750] INFO - tor.impl.FileEditorManagerImpl - Project opening took 5372 ms
2018-04-12 10:27:05,704 [ 42753] INFO - Tools.base.JsbtStartupActivity - Found [] for com.intellij.lang.javascript.buildTools.grunt.GruntService
2018-04-12 10:27:05,705 [ 42754] INFO - Tools.base.JsbtStartupActivity - Found [] for com.intellij.lang.javascript.buildTools.gulp.GulpService
2018-04-12 10:27:05,706 [ 42755] INFO - Tools.base.JsbtStartupActivity - Found [] for com.intellij.lang.javascript.buildTools.npm.NpmScriptsService
2018-04-12 10:27:05,755 [ 42804] INFO - rojectCodeStyleSettingsManager - Initialized from default code style settings.
2018-04-12 10:27:07,208 [ 44257] INFO - .diagnostic.PerformanceWatcher - Indexable file iteration took 2324ms; general responsiveness: ok; EDT responsiveness: 1/2 sluggish
2018-04-12 10:27:07,211 [ 44260] INFO - g.FileBasedIndexProjectHandler - Reindexing refreshed files: 8 to update, calculated in 1ms
2018-04-12 10:27:07,622 [ 44671] INFO - .diagnostic.PerformanceWatcher - Reindexing refreshed files took 411ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:07,748 [ 44797] INFO - tartup.impl.StartupManagerImpl - Some post-startup activities freeze UI for noticeable time. Please consider making them DumbAware to do them in background under modal progress, or just making them faster to speed up project opening.
2018-04-12 10:27:07,748 [ 44797] INFO - tartup.impl.StartupManagerImpl - ProjectInspectionProfileStartUpActivity run in 117ms on UI thread
2018-04-12 10:27:07,765 [ 44814] INFO - cloudConfig.CloudConfigManager - === StatusBar.start create ===
2018-04-12 10:27:07,828 [ 44877] INFO - CompilerWorkspaceConfiguration - Available processors: 8
2018-04-12 10:27:08,062 [ 45111] INFO - j.ide.ui.OptionsTopHitProvider - 186 ms spent to cache options in project
2018-04-12 10:27:11,014 [ 48063] INFO - pl.ProjectRootManagerComponent - project roots have changed
2018-04-12 10:27:11,222 [ 48271] INFO - .diagnostic.PerformanceWatcher - Pushing properties took 8ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:11,565 [ 48614] INFO - .diagnostic.PerformanceWatcher - Indexable file iteration took 342ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:11,565 [ 48614] INFO - indexing.UnindexedFilesUpdater - Unindexed files update started: 6 files to update
2018-04-12 10:27:11,618 [ 48667] INFO - .diagnostic.PerformanceWatcher - Unindexed files update took 53ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:11,998 [ 49047] WARN - ess.util.ProgressIndicatorBase - This progress indicator is indeterminate, this may lead to visual inconsistency. Please call setIndeterminate(false) before you start progress.
2018-04-12 10:27:12,527 [ 49576] INFO - .diagnostic.PerformanceWatcher - Pushing properties took 1ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:12,566 [ 49615] INFO - .diagnostic.PerformanceWatcher - Indexable file iteration took 39ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:19,267 [ 56316] INFO - il.indexing.FileBasedIndexImpl - Rebuild requested for index IgnoreFilesIndex
java.lang.NullPointerException
at com.intellij.util.indexing.impl.ValueContainerImpl.saveTo(ValueContainerImpl.java:410)
at com.intellij.util.indexing.impl.ChangeTrackingValueContainer.saveTo(ChangeTrackingValueContainer.java:163)
at com.intellij.util.indexing.impl.ValueContainerMap$ValueContainerExternalizer.save(ValueContainerMap.java:78)
at com.intellij.util.indexing.impl.ValueContainerMap$ValueContainerExternalizer.save(ValueContainerMap.java:69)
at com.intellij.util.io.PersistentHashMap.doPut(PersistentHashMap.java:392)
at com.intellij.util.indexing.impl.ValueContainerMap.doPut(ValueContainerMap.java:64)
at com.intellij.util.indexing.impl.ValueContainerMap.doPut(ValueContainerMap.java:28)
at com.intellij.util.io.PersistentHashMap.put(PersistentHashMap.java:377)
at com.intellij.util.indexing.impl.MapIndexStorage$3.onDropFromCache(MapIndexStorage.java:132)
at com.intellij.util.indexing.impl.MapIndexStorage$3.onDropFromCache(MapIndexStorage.java:99)
at com.intellij.util.containers.SLRUMap.clear(SLRUMap.java:148)
at com.intellij.util.indexing.impl.MapIndexStorage.flush(MapIndexStorage.java:156)
at com.intellij.util.indexing.VfsAwareMapIndexStorage.flush(VfsAwareMapIndexStorage.java:106)
at com.intellij.util.indexing.MemoryIndexStorage.flush(MemoryIndexStorage.java:127)
at com.intellij.util.indexing.impl.MapReduceIndex.doFlush(MapReduceIndex.java:148)
at com.intellij.util.indexing.VfsAwareMapReduceIndex.doFlush(VfsAwareMapReduceIndex.java:192)
at com.intellij.util.indexing.impl.MapReduceIndex.flush(MapReduceIndex.java:127)
at com.intellij.util.indexing.FileBasedIndexImpl.flushAllIndices(FileBasedIndexImpl.java:600)
at com.intellij.util.indexing.FileBasedIndexImpl.access$4600(FileBasedIndexImpl.java:117)
at com.intellij.util.indexing.FileBasedIndexImpl$FileIndexDataInitialization$1.run(FileBasedIndexImpl.java:2443)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
at com.intellij.util.concurrency.SchedulingWrapper$MyScheduledFutureTask.run(SchedulingWrapper.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
2018-04-12 10:27:20,229 [ 57278] INFO - ntellij.analysis.SonarLintTask - Running SonarLint Analysis for 'DemoApplication.kt'
2018-04-12 10:27:20,496 [ 57545] INFO - il.indexing.FileBasedIndexImpl - scheduleIndexRebuild, reason: checkRebuild
2018-04-12 10:27:20,674 [ 57723] INFO - .diagnostic.PerformanceWatcher - Pushing properties took 1ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:20,978 [ 58027] INFO - ntellij.analysis.SonarLintTask - SonarLint analysis done
2018-04-12 10:27:21,389 [ 58438] INFO - .diagnostic.PerformanceWatcher - Indexable file iteration took 700ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:21,389 [ 58438] INFO - indexing.UnindexedFilesUpdater - Unindexed files update started: 2 files to update
2018-04-12 10:27:21,442 [ 58491] INFO - .diagnostic.PerformanceWatcher - Unindexed files update took 53ms; general responsiveness: ok; EDT responsiveness: ok
2018-04-12 10:27:36,211 [ 73260] INFO - g.FileBasedIndexProjectHandler - Reindexing refreshed files: 0 to update, calculated in 0ms
2018-04-12 10:29:34,031 [ 191080] INFO - j.compiler.server.BuildManager - Clearing project build data because the project does not exist or was not opened for more than 30 days: /Users/marc/Library/Caches/IntelliJIdea2018.1/compile-server/spring_fdcbae4

Check if you have *.kt and *.java file extensions in Registered patterns for the Text file type in settings:

No, *.java and *.kt are not registered as Text types.

I found some that is probably related to this issue. When trying to load an old project I do get the following errors:

Yep, you have Kotling plugin disabled. Please enable it in Preferences | Plugins. If it is not compatible with current IDE version, run IntelliJ IDEA | Check for Updates... action for an update.

Jep, solved. Thnx.