Some of my feeds just got jammed for some unknown reason. Selecting them in the Feed Subscriptions window did not enable the Remove button, preventing me from unsubscribe from them (with the intention of then resubscribing). Next I tried deleting them, then deleting them from the Trash. Astonishingly fully deleting the feed folders has not unsubscribed me from the feeds, since if I try to subscribe to these feeds I get told I already have a subscription! So it seems like Thunderbird has completely screwed me and has no workarounds to get these feeds back.
Jwatt did you try deleting the folders in the profile ?
(this isn't dataloss afaict) I don't claim to know the collection of RSS bugs, but perhaps your issue is in this list https://bugzilla.mozilla.org/buglist.cgi?type1-0-0=substring&list_id=331409&field0-0-0=short_desc&bug_severity=blocker&bug_severity=critical&bug_severity=major&bug_severity=normal&type0-0-1=substring&field0-0-1=keywords&type1-0-1=allwordssubstr&resolution=---&classification=Client%20Software&classification=Components&query_format=advanced&longdesc=unsubscrib%20subscrib&type0-0-0=anywordssubstr&component=Feed%20Reader&field1-0-0=short_desc&longdesc_type=allwordssubstr&product=MailNews%20Core&product=Thunderbird&field1-0-1=short_desc
Ludo: the folders no longer exist in the profile, so Thunderbird did delete them. Wayne: I had directories full of archived and tagged blog posts, which for some reason got lost all their contents and got jammed preventing further blog posts from arriving in them, so it's certainly dataloss. Even if the bug that is preventing me from resubscribing to those feeds is fixed, I'll never get back those archived and tagged posts.
I guess the rdf file got corrupted. You still have the feed files from your profile are these are gone too ?
fixed by bug 711173/bug 705504.