Cannot read property 'anchor' of undefined

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To Reproduce
Steps to reproduce the behavior:

Install C++ Helper extension.
Add a declaration to a class in a C++ header file.
Right click on the function and select "Create Implementation".
See error.

VSCodeVim version: 1.21.7

Stack trace

TypeError: Cannot read property 'anchor' of undefined
    at I.syncCursors (c:\rw_apps\vscode\data\extensions\vscodevim.vim-1.21.7\src\mode\modeHandler.ts:112:66)
    at E (c:\rw_apps\vscode\data\extensions\vscodevim.vim-1.21.7\extensionBase.ts:57:16)
    at runMicrotasks (<anonymous>)
    at process.mh (internal/process/task_queues.js:93:5)
    at c:\rw_apps\vscode\data\extensions\vscodevim.vim-1.21.7\extensionBase.ts:262:15

After the initial error occurs, I'm also getting "Failed to handle key=(. Cannot read property 'active' of undefined".

Stack trace

TypeError: Failed to handle key=(. Cannot read property 'active' of undefined
    at c.recalculateSearchRanges (c:\rw_apps\vscode\data\extensions\vscodevim.vim-1.21.7\src\state\searchState.ts:196:53)
    at c.getMatchRanges (c:\rw_apps\vscode\data\extensions\vscodevim.vim-1.21.7\src\state\searchState.ts:50:17)
    at I.updateSearchHighlights (c:\rw_apps\vscode\data\extensions\vscodevim.vim-1.21.7\src\mode\modeHandler.ts:1135:47)
    at I.updateView (c:\rw_apps\vscode\data\extensions\vscodevim.vim-1.21.7\src\mode\modeHandler.ts:1533:11)
    at I.handleKeyAsAnAction (c:\rw_apps\vscode\data\extensions\vscodevim.vim-1.21.7\src\mode\modeHandler.ts:672:16)
    at runMicrotasks (<anonymous>)
    at process.handledAsAction (internal/process/task_queues.js:93:5)
    at I.text [as handleKeyEvent] (c:\rw_apps\vscode\data\extensions\vscodevim.vim-1.21.7\src\mode\modeHandler.ts:477:11)
    at c:\rw_apps\vscode\data\extensions\vscodevim.vim-1.21.7\extensionBase.ts:370:73

Reproduce the failure with the C++ Helper extension and inspect src/mode/modeHandler.ts at syncCursors and src/state/searchState.ts at recalculateSearchRanges. Trace how the missing cursor or state reaches both stack traces; done means the Create Implementation workflow no longer raises either reported error.

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