forum.cohlerclassical.com

In order to track down the origin of some problems, I did a complete clean installation of Reaper and Cohler Classical (CC). Checking the UserPlugins folder shows only 3 files in that directory, while the CC installer says there should be 5, as seen on the right in the screenshot below.
Should I manually drag the files from the installer to the UserPlugins folder? Or is it correct with 3 files?

No, three files is correct. It says "will be installed", i.e. you don't have to do anything.

In any case, the up-to-date install procedure is always on the website at https://cohlerclassical.com/install/ and accessible in the menu at TRY => Install

I will remove the verbiage from the disk image, however, to avoid confusion going forward. Follow only the instructions that are in the Quick Start Guide and the website.

Also, you should almost never have to reinstall Cohler Classical once it is installed. Same goes for REAPER. The auto-updates should always keep you in good shape.