Argument for @NotNull parameter 'file' of com/intellij/openapi/roots/impl/ProjectFileIndexImpl.getModuleForFile must not be null

[holysky5]

Argument for @NotNull parameter 'file' of com/intellij/openapi/roots/impl/ProjectFileIndexImpl.getModuleForFile must not be null
java.lang.IllegalArgumentException: Argument for @NotNull parameter 'file' of com/intellij/openapi/roots/impl/ProjectFileIndexImpl.getModuleForFile must not be null
at com.intellij.openapi.roots.impl.ProjectFileIndexImpl.getModuleForFile(ProjectFileIndexImpl.java)
at ch.raffael.doclets.pegdown.integrations.idea.DocCommentProcessor.(DocCommentProcessor.java:101)
at ch.raffael.doclets.pegdown.integrations.idea.PegdownDocumentationProvider.generateDoc(PegdownDocumentationProvider.java:127)
at com.intellij.lang.documentation.CompositeDocumentationProvider.generateDoc(CompositeDocumentationProvider.java:144)
at com.intellij.codeInsight.navigation.CtrlMouseHandler.a(CtrlMouseHandler.java:659)
at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:931)
at com.intellij.codeInsight.navigation.CtrlMouseHandler.a(CtrlMouseHandler.java:656)
at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.java:223)
at com.intellij.util.Alarm$Request.runSafely(Alarm.java:418)
at com.intellij.util.Alarm$Request.access$700(Alarm.java:343)
at com.intellij.util.Alarm$Request$1.run(Alarm.java:385)
at com.intellij.util.Alarm$Request.run(Alarm.java:396)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at com.intellij.util.concurrency.SchedulingWrapper$MyScheduledFutureTask.run(SchedulingWrapper.java:237)
at com.intellij.util.concurrency.BoundedTaskExecutor$2.run(BoundedTaskExecutor.java:212)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)