As a result of some changes in the UBT code, it seems that the right-click, generate project files command will no longer (under some circumstances anyway) display a dialog on failure, but just finish without any feedback about why they couldn’t be generated.
In particular, I’m getting this when trying to generate 4.16 project files for a project which has dependencies on plugins which I do not yet have installed for 4.16. By debugging I’ve found the output error is
ERROR: Couldn't find module rules file for module ''.
I believe this should be generating an error dialog, but is not doing on 4.16. This is liable to lead to a lot of confusion with updating of projects if not fixed soon.