If you link your account and then zip-up the Collections, Libraries and Photo Sharing folders below /dopusdata, I'll see if I can work out which file is causing the problem.
(To go to the configuration folder, type /dopusdata into the location bar or directly into the file display. You should then see some of the directories I mentioned, along with some others. It's also possible that some of them won't be there; e.g. if you've never used the Photo Sharing stuff then that dir may not be there, which is fine.)
(You can send the zip via a private message if you don't want to make it public.)
The problem is triggered by one of your Flickr collections, due to a combination of a long name and a special character:
Rodger E Clark(Pool) ₪ HDR & PS Post-Processing ₪ (Add 1 ~ Award 2)
(The collection with the same name but in the root Collections folder is OK. It's only the one below the named folder that's causing the problem, I think only because the extra folder name makes the path longer.)
You can avoid the problem by either removing the two ₪ characters or making the name slightly shorter. For example, both of these will be OK:
Rodger E Clark(Pool) - HDR & PS Post-Processing - (Add 1 ~ Award 2) Rodger E Clark(Pool) ₪ HDR & PS Post-Processing ₪ (Add1~Award2)
At the moment, any non-ascii characters in config file names will cause the backup to encode those names using quite a verbose method, which in turn can run into problems with filename length limits in zip archives. We don't technically need to do this encoding anymore, but if we turn it off we'll make it so that config backups cannot be used with previous versions of Opus. It's something we may change in a major version, where such a break in backward compatibility makes more sense, but that we're unfortunately stuck with for the time being.