Input quirks caused by an IndexOutOfBoundsException. Maybe Mac OS specific?

[rasmniel]

I'm coding on Mac Sierra using PHPStorm.
Occasionally I get inexplicable input lag and sometimes entirely omitted keypresses like pressing return not resulting in newline and other keyboard response-quirks
Triggers randomly and persists from initial occurrence, suspecting that middle click may trigger the abnormalities.

PHPStorm gives me the following error, telling me that the SilverStripe Template Language Support fails. Although I am not entirely certain the error occurs inside *.ss files only, that could be the case.

Let me know if more info is required to pinpoint the error.

Index out of range: -1
java.lang.IndexOutOfBoundsException: Index out of range: -1
	at com.intellij.util.text.ImmutableText.findLeaf(ImmutableText.java:263)
	at com.intellij.util.text.ImmutableText.charAt(ImmutableText.java:255)
	at com.intellij.openapi.editor.impl.DocumentImpl$1.charAt(DocumentImpl.java:98)
	at com.raket.silverstripe.editor.actions.SilverStripeEnterHandler.isBetweenHbTags(SilverStripeEnterHandler.java:56)
	at com.raket.silverstripe.editor.actions.SilverStripeEnterHandler.preprocessEnter(SilverStripeEnterHandler.java:41)
	at com.intellij.codeInsight.editorActions.EnterHandler.a(EnterHandler.java:128)
	at com.intellij.codeInsight.editorActions.EnterHandler.b(EnterHandler.java:81)
	at com.intellij.psi.impl.source.PostprocessReformattingAspect.lambda$disablePostprocessFormattingInside$1(PostprocessReformattingAspect.java:111)
	at com.intellij.psi.impl.source.PostprocessReformattingAspect.disablePostprocessFormattingInside(PostprocessReformattingAspect.java:119)
	at com.intellij.psi.impl.source.PostprocessReformattingAspect.disablePostprocessFormattingInside(PostprocessReformattingAspect.java:110)
	at com.intellij.codeInsight.editorActions.EnterHandler.executeWriteAction(EnterHandler.java:80)
	at com.intellij.openapi.editor.actionSystem.EditorWriteActionHandler$1.run(EditorWriteActionHandler.java:51)
	at com.intellij.openapi.application.impl.ApplicationImpl.runWriteAction(ApplicationImpl.java:1003)
	at com.intellij.openapi.editor.actionSystem.EditorWriteActionHandler.doExecute(EditorWriteActionHandler.java:64)
	at com.intellij.openapi.editor.actionSystem.EditorActionHandler.execute(EditorActionHandler.java:210)
	at com.intellij.codeInsight.template.impl.editorActions.EnterHandler.executeWriteAction(EnterHandler.java:49)
	at com.intellij.openapi.editor.actionSystem.EditorWriteActionHandler$1.run(EditorWriteActionHandler.java:51)
	at com.intellij.openapi.application.impl.ApplicationImpl.runWriteAction(ApplicationImpl.java:1003)
	at com.intellij.openapi.editor.actionSystem.EditorWriteActionHandler.doExecute(EditorWriteActionHandler.java:64)
	at com.intellij.openapi.editor.actionSystem.EditorActionHandler.lambda$null$2(EditorActionHandler.java:202)
	at com.intellij.openapi.editor.actionSystem.EditorActionHandler.doIfEnabled(EditorActionHandler.java:110)
	at com.intellij.openapi.editor.actionSystem.EditorActionHandler.lambda$execute$3(EditorActionHandler.java:201)
	at com.intellij.openapi.editor.impl.CaretModelImpl.a(CaretModelImpl.java:363)
	at com.intellij.openapi.editor.impl.CaretModelImpl.doWithCaretMerging(CaretModelImpl.java:452)
	at com.intellij.openapi.editor.impl.CaretModelImpl.runForEachCaret(CaretModelImpl.java:355)
	at com.intellij.openapi.editor.impl.CaretModelImpl.runForEachCaret(CaretModelImpl.java:346)
	at com.intellij.openapi.editor.actionSystem.EditorActionHandler.execute(EditorActionHandler.java:201)
	at com.jetbrains.php.framework.FrameworkEditorActionHandler.executeNext(FrameworkEditorActionHandler.java:327)
	at com.jetbrains.php.framework.FrameworkEditorActionHandler.executeWriteAction(FrameworkEditorActionHandler.java:94)
	at com.intellij.openapi.editor.actionSystem.EditorWriteActionHandler$1.run(EditorWriteActionHandler.java:51)
	at com.intellij.openapi.application.impl.ApplicationImpl.runWriteAction(ApplicationImpl.java:1003)
	at com.intellij.openapi.editor.actionSystem.EditorWriteActionHandler.doExecute(EditorWriteActionHandler.java:64)
	at com.intellij.openapi.editor.actionSystem.EditorActionHandler.lambda$execute$4(EditorActionHandler.java:207)
	at com.intellij.openapi.editor.actionSystem.EditorActionHandler.doIfEnabled(EditorActionHandler.java:110)
	at com.intellij.openapi.editor.actionSystem.EditorActionHandler.execute(EditorActionHandler.java:206)
	at com.intellij.openapi.editor.actionSystem.EditorAction.lambda$actionPerformed$0(EditorAction.java:98)
	at com.intellij.openapi.command.impl.CoreCommandProcessor.a(CoreCommandProcessor.java:149)
	at com.intellij.openapi.command.impl.CoreCommandProcessor.executeCommand(CoreCommandProcessor.java:109)
	at com.intellij.openapi.editor.actionSystem.EditorAction.actionPerformed(EditorAction.java:107)
	at com.intellij.openapi.editor.actionSystem.EditorAction.actionPerformed(EditorAction.java:86)
	at com.intellij.openapi.actionSystem.ex.ActionUtil$1.run(ActionUtil.java:220)
	at com.intellij.openapi.actionSystem.ex.ActionUtil.performActionDumbAware(ActionUtil.java:237)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher$1.performAction(IdeKeyEventDispatcher.java:576)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher.a(IdeKeyEventDispatcher.java:625)
	at com.intellij.openapi.application.TransactionGuardImpl.performUserActivity(TransactionGuardImpl.java:195)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher.processAction(IdeKeyEventDispatcher.java:624)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher.e(IdeKeyEventDispatcher.java:479)
	at com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher.dispatchKeyEvent(IdeKeyEventDispatcher.java:213)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:622)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:366)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)