'UI' does not exist in the namespace 'UnityEngine'

Question

I've tried a lot of things already but nothing worked.

I've already reimported, deleted, and reinstalled stuff. I'm using unity 2019.3.0f6 and vs code 1.42.1.

Answer 1

I found the answer here. https://issuetracker.unity3d.com/issues/upgrading-projects-to-2019-dot-2-0b1-can-introduce-reference-errors-to-unityengine-dot-ui

For those who are facing this problem yet:

1. Remove all .sln and .csproj files

2. Make sure the "Generate all .csproj files." checkbox is checked on Preferences

3. Reopen C# Project

The guy on the comments showed something that even the official VS Code and Unity Integration page didn't mention. And the integration page is already very old. The Unity ui shown there is already different compared to the current 2019.3.0f6 that I am using.