Cannot phpMyAdmin a certain DB "The page isn’t redirecting properly"

Hy guys,

I am trying to back up a WP-DB (“rfgd_20117703_w926”) via phpMyAdmin.

But Firefox gives me an error “The page isn’t redirecting properly”.

Trying to troubleshoot the issue I created another DB (“rfgd_20117703_test”) for my account. For this DB phpMyAdmin starts without error.

What can be wrong?

Thanks and best regards, rfgd_20117703