We have a modified menus.pas.
At
uses ...,Controls,...;
The compiler raised a fatal error:
[DCC Fatal Error] Menus.pas(*): F2051 Unit Controls was compiled with a different version of Menus.TPopupMenu
tried:
deleted all dcu in the project.
build
build all
tried adding the file to library path which leads to add db folder(from vcl too) and then to
[DCC Error] jpeg.pas(872): E2065 Unsatisfied forward or external declaration: 'jpeg_save_markers'
which is a dead end.
deleted the controls.dcu (all 3) and the delphi did not know automaticaly to recompile them, instead reported that controls.dcu is missing.
Here is how I handle modifications to VCL source files:
I'd guess that one of the final two bullet points is what is tripping you up.