Help migrating/upgrading

Hello - we switched to a new host last year and have been trying to migrate a Gallery installation. The developer who set up our original server is no longer with us and our new host does not have much experience with Gallery. The installation (which was Gallery 2) was working fine on the old host before we moved it.

After migration, we are getting the upgrade screen when I go to the Gallery2 directory. When I try to complete the upgrade the errors (attached file) are shown.

I would really appreciate any advice offered. Sadly now the old host I believe has been shut down so I don't have the old set up to rollback to.

Thanks in advance for any suggestions/help.

Thanks for your quick reply! It is possible that the installation was in a state of lapsed maintenance before we started the migration - but I do know that it had been upgraded to version 2.... whether it was a full release or alpha I'm not certain. I'm not able to see the contents of the .dat file.

I checked the permissions and they are accessible - I'm wondering if there is a way to do a clean install instead of upgrading? Will it be possible to migrate the old database? Please be patient as I am not a techie - I also don't have shell access to this server, ftp only - so I need to convey instructions for any command line stuff to the support team at the new host =(

Thanks again for your feedback!