One thing that fixed it for me (after switching engine version and regenerating VS solution files by right clicking on the uproject file) was opening the project in Visual Studio and then changing the 2 .Target.cs files (one for the game, one for the editor) and set DefaultBuildSettings to BuildSettingsVersion.Latest, looking like this:
DefaultBuildSettings = BuildSettingsVersion.Latest;
After this I did a rebuild and opened the uproject file and everything was fine. Prior to this VS showed some projects failing to build due to some settings that weren’t allowed anymore.