Visual Studio does not auto-complete anything

Question

I’ve always used visual studio and never had any problems. I have the community 2017 version installed, and I was using normally, however, I had to pause the development I had been doing. Now that I came back (a couple of months later), an update came out and I installed it smoothly. The problem now comes:

The visual studio is no longer suggesting auto-completes of classes, not even Imports/using. It’s working like a Notepad++, it just changes the color of things. When I try to compile, it triggers a lot of errors "missing import", "unreported variable", all this because it is not making the suggestions of anything.

I wanted the help of you to try to solve this problem (I already repaired it in Visual Studio Installer, but did not solve).