1. In the home folder of the user under which you logged in find the folder .phpls , and we carry the entire contents of this folder.
Or using the Nautilus file Manager
Either through the console: rm-rfv ~/.phpls/*
2. Reopens again the project folder which worked.
Immediately warn, will have to wait some time (if the project is huge) while the VS Code will scan the folder again. In my case the project at a half gig.
The solution for Windows users:
You may want to look for a similar folder on the drive :C is also in the folder of the user.