If you have a workspace and for some reason have multiple folders you may need to ‘help’ omnisharp a bit. I initially had a big project and added a solution for it further on – ending up with TWO workspace folders (one to a startup project and one to the solution). After composing that setup I experienced only the first project to have intellisense working.
Solution to get intellisense working was to make sure omnisharp worked its way from the solution instead of the project:
- Ctrl + Shift + p
- Write “OmniSharp: Select Project” and press Enter.
- Choose the solution workspace entry.
Inspiration gotten from ‘swaner’:
https://github.com/OmniSharp/omnisharp-vscode/issues/1889