The UI has a bug where if WordPress/CMS is installed, the folder with the files of the CMS, doesn't compress. When we select all files and click on the compress button the message says compression failed, and there is no error message why it failed. The behavior is very random, most of the times it fails, but sometimes it works.
As hosting providers, we have to log in via Command Line and then compress the folder for them.
Please fix this bug.