unable to get stub builder for org.intellij.plugins.markdown.lang.MarkdownFileType

A user (https://github.com/Potrimpo) of my plugin, IntelliJ Elixir (https://github.com/KronicDeth/intellij-elixir), reported (https://github.com/KronicDeth/intellij-elixir/issues/613) the error

```

unable to get stub builder for org.intellij.plugins.markdown.lang.MarkdownFileType@7017f8, path = /Users/lewis.knoxstreader/zCode/elixir/plugFun/deps/mime/README.md, stubBindingRoot = MarkdownFile, languages = [Markdown], filesTypes = [Markdown], files = [MarkdownFile], roots = []

```

```

java.lang.Throwable at com.intellij.openapi.diagnostic.Logger.error(Logger.java:132) at com.intellij.psi.stubs.StubProcessingHelperBase.processStubsInFile(StubProcessingHelperBase.java:81) at com.intellij.psi.stubs.StubProcessingHelperBase.processStubsInFile(StubProcessingHelperBase.java:52) at com.intellij.psi.stubs.StubIndexImpl$2.process(StubIndexImpl.java:333) at com.intellij.psi.stubs.StubIndexImpl$StubIdListContainerAction.perform(StubIndexImpl.java:684) at com.intellij.psi.stubs.StubIndexImpl$StubIdListContainerAction.perform(StubIndexImpl.java:672) at com.intellij.util.indexing.ValueContainer.forEach(ValueContainer.java:81) at com.intellij.psi.stubs.StubIndexImpl.a(StubIndexImpl.java:359) at com.intellij.psi.stubs.StubIndexImpl.processElements(StubIndexImpl.java:325) at com.intellij.psi.stubs.StubIndex.getElements(StubIndex.java:146) at com.intellij.psi.stubs.StubIndex.getElements(StubIndex.java:135) at org.elixir_lang.psi.scope.module.Variants.addProjectNameElementsTo(Variants.java:279) at org.elixir_lang.psi.scope.module.Variants.lookupElementList(Variants.java:51) at org.elixir_lang.reference.Module.getVariants(Module.java:106) at com.intellij.codeInsight.completion.CompletionData.completeReference(CompletionData.java:292) at com.intellij.codeInsight.completion.CompletionVariant.addReferenceCompletions(CompletionVariant.java:164)

```

Is this a known bug in certain versions of IntelliJ.  Is there any change I can make to my plugin to avoid this in the future? Or, is there a configuration change the user should make to their preferences?  Previously, for https://intellij-support.jetbrains.com/hc/en-us/community/posts/205436610-Unable-to-get-stub-builder-for-com-jetbrains-jsonSchema-JsonSchemaFileType-, Irina Chernushina said JsonSchemaFileType has a similar bug, so was Markdown also affected by this bug?