I resubscribed to the feed and this time it's fine. I believe the problem was caused by a combination of an old version of Thunderbird that used to access the profile, the question mark in the feed title, and perhaps the fact that the profile sits on a FAT partition that can't handle question marks.
I resubscribed to the feed and this time it's fine. I believe the problem was caused by a combination of an old version of Thunderbird that used to access the profile, the question mark in the feed title, and perhaps the fact that the profile sits on a FAT partition that can't handle question marks.