Cannot read property 'clone' of null

[vscode-triage-bot]

TypeError: Cannot read property 'clone' of null
at s in src/vs/editor/common/model/textModelTokens.ts:489:58
at n._updateTokensUntilLine in src/vs/editor/common/model/textModelTokens.ts:400:14
at n.forceTokenization in src/vs/editor/common/model/textModelTokens.ts:315:8
at li.forceTokenization in src/vs/editor/common/model/textModel.ts:2075:22
at li.tokenizeIfCheap in src/vs/editor/common/model/textModel.ts:2084:9
at fs._updateSnippets in src/vs/workbench/contrib/snippets/browser/tabCompletion.ts:87:9
at out/vs/workbench/workbench.desktop.main.js:1799:8878
at a.fire in src/vs/base/common/event.ts:577:16
at out/vs/workbench/workbench.desktop.main.js:723:18565
at a.fire in src/vs/base/common/event.ts:577:16
at R._emitOutgoingEvents in src/vs/editor/common/viewModel/viewModelEventDispatcher.ts:62:18
at R.endEmitViewEvents in src/vs/editor/common/viewModel/viewModelEventDispatcher.ts:107:8
at out/vs/workbench/workbench.desktop.main.js:720:38112
at a.fire in src/vs/base/common/event.ts:577:16
at out/vs/workbench/workbench.desktop.main.js:677:8196
at a.fire in src/vs/base/common/event.ts:577:16
at pe.endDeferredEmit in src/vs/editor/common/model/textModel.ts:3194:23
at li.pushEditOperations in src/vs/editor/common/model/textModel.ts:1305:23
at h.updateModel in src/vs/editor/common/services/modelServiceImpl.ts:437:9
at sn.updateTextEditorModel in src/vs/workbench/common/editor/textEditorModel.ts:195:22
at sn.doUpdateTextModel in src/vs/workbench/services/textfile/common/textFileEditorModel.ts:549:9
at sn.resolveFromContent in src/vs/workbench/services/textfile/common/textFileEditorModel.ts:511:9
at sn.resolveFromFile in src/vs/workbench/services/textfile/common/textFileEditorModel.ts:443:16
at async o.doResolve in out/vs/workbench/workbench.desktop.main.js:2369:36878
at async o.reload in src/vs/workbench/services/textfile/common/textFileEditorModelManager.ts:322:3
at async Object.factory in src/vs/workbench/services/textfile/common/textFileEditorModelManager.ts:166:6

[alexdima]

I couldn't figure out what would cause the NPE, but I pushed a lot of improvements like 44f7998 , 18e6567 or 4c76c01 . Let's keep an eye out and see if this pops up again.

[alexdima]

This showed up again -- #143048