You probably need the debugger.
> Debug: Download .NET Core debugger
NOTE That require the C# extension to be installed, see Requirements
For issue (red squiggles, references not works, etc), you can try
to restart
> Reload Window
To clear cache of project info
> F#: Clear cache
and to change the workspace/sln
> F#: Change Workspace or Solution
can be changed for repo, workspace or user with
> Preferences: Open User Settings
Some nice editor improvements
// whitespace
"editor.renderWhitespace": "boundary",
// linelens instead of codelens
"editor.codeLens": false,
"FSharp.lineLens.enabled": "replaceCodeLens",
Disable defaults
"editor.minimap.enabled": false,
"workbench.startupEditor": "none"
Enable ionide diagnostics
"FSharp.logLanguageServiceRequests": "both",
"FSharp.logLanguageServiceRequestsOutputWindowLevel": "DEBUG",
Use .net core as preferred msbuild host
"FSharp.msbuildHost": ".net core",