Everything seemed to be working nicely for me with the VHDL Language Server and VHDL by Pu Zhao extensions installed. For some reason all autocomplete stopped working, but there is still the ability to navigate to definitions.
I'm not sure where to start to figure out what went wrong and how to fix it.
Thanks for the bug report. I've managed to reproduce it with the latest VSCode. Strangely, autocomplete works fine in all other editors.
I've fixed it in a development version by upgrading vhdl-tool to use version 3.x of the language server protocol. I still need to do some testing before I release that but I will ping you here when its ready.
Thank you, it's good to hear you're working on it. I was assuming it was something I had done.
It certainly makes my job a lot easier to have this tool, so thanks again for your work.
A fixed version supporting version 3 of the language server protocol is now available from the downloads page.