Simulink Coder: Build Process "Error occurred when generating shared type"

The error occurs, when I change a .m-File. Then I have to delete the slprj-directory, to get the "build process" working again.

Snippet of diagnostic viewer: ### Invoking Target Language Compiler on control_IO.rtw ### Using System Target File: D:\Projekte\ECU\Target.tlc ### Loading TLC function libraries ### Generating TLC interface API for custom data ### Initial pass through model to cache user defined code

Error: Error occurred when generating shared type: The contents of the following objects do not match those in the current slprj directory

Where can I check the build process in detail? I want to set a delete command as near as possible to detection (in target and not in model callbacks).