Cannot select project with omnisharp because of quickPickSeparators

Issue Type: Bug

I’m using the insider build, at first I thought this was because of one machine, but now I have the same behavior on my Mac M1 and my Windows 11 device. Whenever I try to select a project I get the below.

Command ‘OmniSharp: Select Project’ resulted in an error (Extension ‘ms-dotnettools.csharp’ CANNOT use API proposal: quickPickSeparators. Its package.json#enabledApiProposals-property declares: [] but NOT quickPickSeparators. The missing proposal MUST be added and you must start in extension development mode or use the following command line switch: --enable-proposed-api ms-dotnettools.csharp)

Extension version: 1.23.16 VS Code version: Code - Insiders 1.63.0-insider (Universal) (1e473b624f088fc05269891170a8ffa1c84a35a6, 2021-11-25T07:59:08.754Z) OS version: Darwin arm64 21.1.0 Restricted Mode: No

System Info

Item	Value
CPUs	Apple M1 Max (10 x 24)
GPU Status	2d_canvas: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	4, 5, 3
Memory (System)	64.00GB (16.10GB free)
Process Argv	. --crash-reporter-id a3331069-8570-41bd-a870-a2bc43c4f676
Screen Reader	no
VM	0%

A/B Experiments

vsliv695:30137379
vsins829:30139715
vsliv368cf:30146710
vsreu685:30147344
python383:30185418
vspor879:30202332
vspor708:30202333
vspor363:30204092
pythontb:30258533
pythonptprofiler:30281269
vshan820:30294714
pythondataviewer:30285072
vscod805cf:30301675
pythonvspyt200:30323110
bridge0708:30335490
bridge0723:30353136
pythonrunftest32:30365365
pythonf5test824:30361779
javagetstartedt:30350119
pythonvspyt187:30365360
vsaa593:30376534
vsc1dst:30396469
pythonvs932:30404738
vscexrecpromptt2:30397559
vscop804cf:30404767
vs360:30404995

[SkyeBlep]

Quick downgrade command for linux users:

apt-get install code=1.62.3-1637137107

I’m a little surprised this is broken in the default shipping configuration of vscode and the fix hasn’t been deployed yet a month later. Given how important intellisense is, losing it makes vscode basically unusable. Priority up, please?

[victoriaquasar]

In my case my problem was fixed by looking at the sln file and checking that every project was referenced correctly: correct path and name. After that, a simple restart of the VSCode was enough.

I dont even have a solution file, your comment is useless