I saw an update of Unreal Engine from 4.18.0 to 4.18.1, since the disk capacity is not enough, I deleted the old engine and install the new engine version in another disk (The BuildingEscape file is unchanged). However, when I open the new engine and open the c++ file associated with the Unreal file, there are a lot of red wave lines under the identifier and it says identifier (something) is undefined. The red lines are just everywhere. I tried rebuild the code but it is not working. I can’t compile my code in VS now, but in Unreal I can still compile. What should I do?
I manually open the .sln file in visual studio and allow the system to parse it for about 5 mins, and then everything works as before. However, when I open the Unreal project, I can only compile the program in visual studio. Compiling in Unreal engine does nothing at all. The compilation finishes in a second and then nothing changes.