Why I get underline red errors in Visual Studio everywhere ? and how to get rid of it ?
One way to get rid of it is to compile your code. Most of the time you can ignore them as sometimes VS struggle with large codebases like UE4. You can read about this in Documentation. I linked you specific part you need but feel free to read the rest as well!
I already compiled my code but these red underlines are really annoying
All settings are set like in the documentation !! do I need to install unreal debug symboles ? I did not install them because they are 24GB