If you recently updated and wish to revert to a previous version, follow these steps

1. remove or rename the new ePMV and uPy folders made during the update session, e.g., to ePMVunwantedUpdate
2. replace the removed folders with the most recent backup versions simply by removing any numbers from the end of the ePMV and uPy backup folders
3. make sure you revert to ePMV and uPy backup folders that correspond to each other (check the modification dates to get the matching versions)
4. e.g. for the host Cinema 4D on a Mac, use this image of the preference folder as a guide (click to zoom): 
5.