Old problem needs solution

Greetings!

At some point, I'm not even sure when, I apparently had a bad upgrade on
one of my production databases. I'm in a situation now where I've got
my back up against a wall and not sure what to do. The problem is, I'm
receiving this message frequently:

did not find '}' at end of input node

I am currently running version 7.4.7 and am trying to migrate on up to
8. The data is completely available to the application (large forums
database is primary concern), but I can't back it up or do anything with
it aside from let it dig itself deeper.

Does anybody have a suggestion on how to fix this, or some way around
it? I could probably write a script to suck all my data out and push it
back in, but I'm hoping and praying there's something better out there,
hopefully a real honest to goodness fix for it ; )

Thanks,

G