sounds like its looks for something thats not there, might b a pain to fix it. you'll have to go down to 27 then do the incremental updates to 85 lol. or try a wipe and reflash.
Aaron just use this and flash from FRF50 to FRF83, then use the second link in the OP and go from FRF83 to FRF85b
http://android.clients.google.com/packages/passion/signed-passion-FRF83-from-FRF50.38d66b26.zip
Will this flash using a custom recovery or do you need stock?
I used the one from here for people with a custom recovery like Amon_RA. http://htcpedia.com/forum/showthread.php?p=67177#post67177