retopoflow 2.0 installation error

Hello to all! Please tell me and teach! I have Blender 2.79. I installed the retopoflow 2.0 add-on. I immediately received an error warning! traceback (most recent call last)
What is it? How to deal with it???
https://dropmefiles.com/y1Zvy

Welcome. Near top right is the search box. See this thread for some solutions to work through.

My guess is you’ll have to rename the installed addon folder (not the zip file) as only letters, numbers, or underscores work.

Thanks for the answer! Yesterday I read the thread where you helped the artist. and I did the same: renamed the folder to retopoflow_202 and installed a stable Blender 2.79 but did not get any results. Today I tried to place a folder with an addon closer but constantly there was a mistake! ((or the addon simply did not load and a blank screen appeared (((

it turned out to install blender-2.79 on the disk C … user…app data … scripts / addons. But I was happy early, a warning appeared …

forgot to write what was installed on the disk C only zip file…