When I tried to upgrade to 3.0 from 2.03 today, I got the exact same error messages re p01 contact plugin. Messed up my client's website completely.
I'm going to try for a restore, disable p01 contact, then try the upgrade again... wish me luck :/
And if anyone finds a solution to this issue, I'd be very glad to hear it.
Thanks!
edited to add:
In case anyone else is experiencing this issue, this worked: I deleted everything, extracted a backup zip via FTP to go back to version 2.03, disabled the plugin, upgraded GS to 3.0 again, and re-enabled the plugin.
All is well.
I'm going to try for a restore, disable p01 contact, then try the upgrade again... wish me luck :/
And if anyone finds a solution to this issue, I'd be very glad to hear it.
Thanks!
edited to add:
In case anyone else is experiencing this issue, this worked: I deleted everything, extracted a backup zip via FTP to go back to version 2.03, disabled the plugin, upgraded GS to 3.0 again, and re-enabled the plugin.
All is well.