My first install of SugarCRM was long time ago and my current install is maybe 5 years old, following all patches up until today. I also moved from CS to Professional. Along the way we did several modifications in Studio, in Module Builder, and by installing and removing modules via Module loader.

I suspecting my current install of SugarCRM to be slower than necessary. The calender and e-mail is "buggy" (can't enter appointments trough calendar, etc.) just to mention a few observations. I also got long and strange texts in my loggfile. (FATAL ERROR ... Meeting, calendar, etc...)

I noticed that some of the files in the directory modules/ don't match a full set of a new SugarCRM Package. Files that is present in the full install package is missing or is much older in my current install.
My guess is that this is a result of problems during some previous patching. It has happened that the process got stuck.

My question is if it is possible to copy files from full install to the current install and replacing files in:
Any other directory/files that could be copied and directory/files to avoid. Is there some general documentation or recommendations about this?

A clean install and migration is probably the best way but I think it is to much work.
Best Regards