Moving from gnucash 1.8 to 2.0: startup error: "can't parse the URL"

[Bill McSpadden]

I recently updated my Linux system and at the same time, gnucash was updated
(from 1.8 to 2.0.5).

When starting up, I get a "Can't parse the URL <homedir>/.gnucash/FirstTech"
All of my accounts have a similar problem.

Clearly, the new version of gnucash has touched the file: the timestamp 
has changed.
When I examine the file, it is entirely different than what was backed 
up. The backed
up file was a large XML file. What exists now is a small plaintext file.

What happened? Why can I not open my old accounts?

(Note: I've searched the mailing list archives. I found several reports 
of a similar
problem, but no definitive answer. If there is one, could someone please 
point me
to it?)

Thanks,
Bill McSpadden
billmc at cnonline.net