If you have MergeModules in Your project.
And the MergeModules are home made and the contents of these merge modules are also modified
What does a patch do with these MergeModules ?
Please note that a merge module is becomes a part of the MSI when the project is built. Since the patch creation process uses the MSI packages, the same patch rules apply to the merge modules. Therefore, if a modification in a merge module breaks the patch rules, the patch may not work correctly.