Refresh Firefox trashes all add-ons
FF was slow to start ONCE due to FEBE backup problem. It offered me a "tune up" which proceeded, without warning, to delete ALL my installed add-ons, including FEBE. This is unacceptable behavior. It should do one of the following 1) Warn you what will happen if you proceed. 2) Disable, rather than delete, add-ons, so the innocent can be re-enabled. 3) Allow you to select which add-ons should be either deleted or disabled.
I have yet to discover what other damage it's done.
Opaite Mbohovái (2)
That is how the Refresh feature in Firefox works, so always be cautious to use it.
When you use the Firefox Refresh feature then a new profile is created and some personal data (bookmarks and history, form data, tabs) is automatically imported. The current profile folder will be moved to an "Old Firefox Data" folder on the desktop. Installed extensions and other customizations (toolbars, prefs) that you have made are lost and need to be redone.
It is possible to recover data from the "Old Firefox Data" folder on the desktop, but be cautious not to copy corrupted files to avoid carrying over problems.
See also:
To suggest changes to Firefox, you can comment on the following site (click the sad face):