the multifox addon ( https://addons.mozilla.org/en-us/firefox/addon/multifox/ ) lets u open tabs which belong to a different 'profile', which i think is just different cookie profiles.
so i can have facebook open in a normal tab and facebook open in multifox profile 2 and both can be logged in to different accounts.

cookies belonging to multifox tabs are named weirdly like 'facebook.com.facebook-com-2.multifox', 'facebook.com.facebook-com-3.multifox' etc. (depending on the profile and the domain name).
they arent blocked by umatrix because they come from the right source and are probably just stored differently by multifox (this is good)

but when umatrix does its cookie cleanups of blocked cookies, it deletes multifox cookies even though they were never blocked ( i guess because it cant find that they belong to any tabs or something ), ive had one other addon have issues with multifox cookies like this. im not sure if addons are able to tell whether or not multifox tabs are open and if cookies belong to them. i think it might be though as the session manager addon remembers which tabs are multifox profiles when saving/restoring sessions.

log from umatrix:

14:50:56        cookie deleted: http://facebook.com.facebook-com-2.multifox/{session-cookie:wd}
14:50:56        cookie deleted: https://facebook.com.facebook-com-2.multifox/{session-cookie:presence}
14:50:56        cookie deleted: https://facebook.com.facebook-com-2.multifox/{session-cookie:xs}
14:50:56        cookie deleted: http://facebook.com.facebook-com-2.multifox/{session-cookie:_js_datr}
14:50:56        cookie deleted: http://youtube.com.youtube-com-2.multifox/{session-cookie:YSC}

would it be possible to not delete .multifox cookies when doing the blocked cookie cleanup (maybe until someone can figure out if other addons can detect multifox tabs/cookies)? i guess its kind of a bug since they were never even blocked tho

also; https://github.com/hultmann/multifox