Error creating or configuring sdk

Hi,

I'm using Intellij Idea Ultimat 2019.1 and tried to add a Ruby-SDK which failed because of the following error in the idea.log file:

2019-04-03 16:48:33,868 [ 115825] WARN - oots.impl.SdkConfigurationUtil - Error creating or configuring sdk: homeDir=[file:///Users/myhome/.rvm/rubies/ruby-2.3.7/bin/ruby]; sdkType=[RUBY_SDK]; additionalData=[org.jetbrains.plugins.ruby.ruby.sdk.RubySdkAdditionalData@e68e2b0d]; customSdkSuggestedName=[RVM: ruby-2.3.7 [global]]; sdk=[RVM: ruby-2.3.7 [global] (/Users/myhome/.rvm/rubies/ruby-2.3.7/bin/ruby)]
java.lang.NoClassDefFoundError: com/intellij/docker/remote/DockerCredentialsType
at com.intellij.docker.remote.ruby.RubyDockerUtil.isRubyDockerSdkAdditionalData(RubyDockerUtil.java:25)
at com.intellij.docker.remote.ruby.RubyDockerSdkConfigurator.supports(RubyDockerSdkConfigurator.java:20)
at org.jetbrains.plugins.ruby.ruby.sdk.RubySdkConfigurator.from(RubySdkConfigurator.java:74)
at org.jetbrains.plugins.ruby.ruby.sdk.RubySdkType.setupSdkPaths(RubySdkType.java:293)
at com.intellij.openapi.projectRoots.impl.SdkConfigurationUtil.setupSdk(SdkConfigurationUtil.java:156)
at org.jetbrains.plugins.ruby.ruby.sdk.RubySdkType.createAndAddLocalSdk(RubySdkType.java:479)
at org.jetbrains.plugins.ruby.version.management.SdkRefresherBase.doRefreshSDKs(SdkRefresherBase.java:144)
at org.jetbrains.plugins.ruby.version.management.AbstractSdkRefresher.refreshSDKs(AbstractSdkRefresher.java:63)
at org.jetbrains.plugins.ruby.version.management.AbstractSdkRefresher$1.run(AbstractSdkRefresher.java:99)
at com.intellij.openapi.progress.impl.CoreProgressManager$TaskRunnable.run(CoreProgressManager.java:731)
at com.intellij.openapi.progress.impl.CoreProgressManager$5.run(CoreProgressManager.java:442)
at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$2(CoreProgressManager.java:164)
at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:586)
at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:532)
at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:86)
at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:151)
at com.intellij.openapi.application.impl.ApplicationImpl.lambda$null$10(ApplicationImpl.java:594)
at com.intellij.openapi.application.impl.ApplicationImpl$1.run(ApplicationImpl.java:311)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

Could you please help to solve this issue?

Best

Long