Exception: Invalid lookup element: liftweb

I'm getting the following exception very often:

{code}
Invalid lookup element: liftweb
java.lang.Throwable
    at com.intellij.openapi.diagnostic.Logger.error(Logger.java:113)
    at com.intellij.codeInsight.completion.impl.CompletionServiceImpl$CompletionResultSetImpl.addElement(CompletionServiceImpl.java:132)
    at org.jetbrains.plugins.scala.lang.completion.ScalaCompletionContributor$$anon$2.org$jetbrains$plugins$scala$lang$completion$ScalaCompletionContributor$$anon$$addElement$1(ScalaCompletionContributor.scala:78)
    at org.jetbrains.plugins.scala.lang.completion.ScalaCompletionContributor$$anon$2$$anonfun$org$jetbrains$plugins$scala$lang$completion$ScalaCompletionContributor$$anon$$applyVariant$default$2$1$1.apply(ScalaCompletionContributor.scala:85)
    at org.jetbrains.plugins.scala.lang.completion.ScalaCompletionContributor$$anon$2$$anonfun$org$jetbrains$plugins$scala$lang$completion$ScalaCompletionContributor$$anon$$applyVariant$default$2$1$1.apply(ScalaCompletionContributor.scala:85)
    at org.jetbrains.plugins.scala.lang.completion.ScalaCompletionContributor$$anon$2.org$jetbrains$plugins$scala$lang$completion$ScalaCompletionContributor$$anon$$applyVariant$1(ScalaCompletionContributor.scala:127)
    at org.jetbrains.plugins.scala.lang.completion.ScalaCompletionContributor$$anon$2$$anonfun$org$jetbrains$plugins$scala$lang$completion$ScalaCompletionContributor$$anon$$postProcessMethod$1$1.apply(ScalaCompletionContributor.scala:141)
    at org.jetbrains.plugins.scala.lang.completion.ScalaCompletionContributor$$anon$2$$anonfun$org$jetbrains$plugins$scala$lang$completion$ScalaCompletionContributor$$anon$$postProcessMethod$1$1.apply(ScalaCompletionContributor.scala:141)
    at scala.collection.immutable.List.foreach(List.scala:318)
    at org.jetbrains.plugins.scala.lang.completion.ScalaCompletionContributor$$anon$2.org$jetbrains$plugins$scala$lang$completion$ScalaCompletionContributor$$anon$$postProcessMethod$1(ScalaCompletionContributor.scala:141)
    at org.jetbrains.plugins.scala.lang.completion.ScalaCompletionContributor$$anon$2$$anonfun$completionProcessor$default$3$1$1.apply(ScalaCompletionContributor.scala:146)
    at org.jetbrains.plugins.scala.lang.completion.ScalaCompletionContributor$$anon$2$$anonfun$completionProcessor$default$3$1$1.apply(ScalaCompletionContributor.scala:146)
    at org.jetbrains.plugins.scala.lang.resolve.processor.CompletionProcessor.changedLevel(CompletionProcessor.scala:173)
    at org.jetbrains.plugins.scala.lang.resolve.ResolvableReferenceExpression$class.treeWalkUp$1(ResolvableReferenceExpression.scala:109)
    at org.jetbrains.plugins.scala.lang.resolve.ResolvableReferenceExpression$class.resolveUnqualifiedExpression(ResolvableReferenceExpression.scala:124)
    at org.jetbrains.plugins.scala.lang.resolve.ResolvableReferenceExpression$class.resolveUnqalified(ResolvableReferenceExpression.scala:95)
    at org.jetbrains.plugins.scala.lang.resolve.ResolvableReferenceExpression$class.doResolve(ResolvableReferenceExpression.scala:75)
    at org.jetbrains.plugins.scala.lang.psi.impl.expr.ScReferenceExpressionImpl.doResolve(ScReferenceExpressionImpl.scala:40)
    at org.jetbrains.plugins.scala.lang.completion.ScalaCompletionContributor$$anon$2.addCompletions(ScalaCompletionContributor.scala:165)
    at com.intellij.codeInsight.completion.CompletionProvider.addCompletionVariants(CompletionProvider.java:36)
    at com.intellij.codeInsight.completion.CompletionContributor.fillCompletionVariants(CompletionContributor.java:155)
    at com.intellij.codeInsight.completion.CompletionService.getVariantsFromContributors(CompletionService.java:84)
    at com.intellij.codeInsight.completion.CompletionResultSet.runRemainingContributors(CompletionResultSet.java:132)
    at com.intellij.codeInsight.completion.CompletionResultSet.runRemainingContributors(CompletionResultSet.java:125)
    at com.intellij.codeInsight.template.impl.LiveTemplateCompletionContributor$1.addCompletions(LiveTemplateCompletionContributor.java:75)
    at com.intellij.codeInsight.completion.CompletionProvider.addCompletionVariants(CompletionProvider.java:36)
    at com.intellij.codeInsight.completion.CompletionContributor.fillCompletionVariants(CompletionContributor.java:155)
    at com.intellij.codeInsight.completion.CompletionService.getVariantsFromContributors(CompletionService.java:84)
    at com.intellij.codeInsight.completion.CompletionService.performCompletion(CompletionService.java:115)
    at com.intellij.codeInsight.completion.CompletionProgressIndicator.a(CompletionProgressIndicator.java:769)
    at com.intellij.codeInsight.completion.CompletionProgressIndicator.access$900(CompletionProgressIndicator.java:84)
    at com.intellij.codeInsight.completion.CompletionProgressIndicator$1CalculateItems.run(CompletionProgressIndicator.java:751)
    at com.intellij.codeInsight.completion.AsyncCompletion$1$1$1.run(CompletionThreading.java:93)
    at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:911)
    at com.intellij.codeInsight.completion.AsyncCompletion$1$1.run(CompletionThreading.java:88)
    at com.intellij.openapi.progress.impl.ProgressManagerImpl$2.run(ProgressManagerImpl.java:178)
    at com.intellij.openapi.progress.ProgressManager.executeProcessUnderProgress(ProgressManager.java:209)
    at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:212)
    at com.intellij.openapi.progress.impl.ProgressManagerImpl.runProcess(ProgressManagerImpl.java:171)
    at com.intellij.codeInsight.completion.AsyncCompletion$1.run(CompletionThreading.java:84)
    at com.intellij.openapi.application.impl.ApplicationImpl$8.run(ApplicationImpl.java:419)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:724)
    at com.intellij.openapi.application.impl.ApplicationImpl$1$1.run(ApplicationImpl.java:149)
2014-03-14 16:08:11,570 [24549567]  ERROR - ion.impl.CompletionServiceImpl - IntelliJ IDEA (Cardea) IU-135.406  Build #IU-135.406
2014-03-14 16:08:11,570 [24549567]  ERROR - ion.impl.CompletionServiceImpl - JDK: 1.7.0_40
2014-03-14 16:08:11,570 [24549567]  ERROR - ion.impl.CompletionServiceImpl - VM: Java HotSpot(TM) 64-Bit Server VM
2014-03-14 16:08:11,570 [24549567]  ERROR - ion.impl.CompletionServiceImpl - Vendor: Oracle Corporation
2014-03-14 16:08:11,571 [24549568]  ERROR - ion.impl.CompletionServiceImpl - OS: Linux
2014-03-14 16:08:11,571 [24549568]  ERROR - ion.impl.CompletionServiceImpl - Last Action: EditorSelectWord
{code}

I've reported it many times using "Report to JetBrains" but it hasn't been addressed.

Any hints on what's causing it or what I can do to provide more info about the error?