Had the same problem switching form 4.11 to 4.12 (on Mac).
To solve I had to deleted the Saved folder AND rename my project file (the yourprojectname.uproject file inside the project folder)
After doing it, no more warnings at all.
Hope it helps.
Had the same problem switching form 4.11 to 4.12 (on Mac).
To solve I had to deleted the Saved folder AND rename my project file (the yourprojectname.uproject file inside the project folder)
After doing it, no more warnings at all.
Hope it helps.