Can't Retrieve Password After Upgrade (Failed And Rolled Back

[Aagje Vanden Bussche]

I tried to upgrade my 1.5.6.0 to a 1.5.6.3, but it failed. So I rolled back to the last backup (this morning). Yet, not everything was correct, so my hosting provide put back the backup per ftp. 

Now I cannot retrieve my admin password. When clicking on the 'Lost password?' link, I can fill in the email address, but when confirming, I get an error 

 

 

TECHNICAL ERROR:

Details: Error thrown: [object Object]

Text status: parsererror

 

And then I do get an email with a new password, that does not work to log in.

 

Can someone help me with this?