Exception in Designer if SQL Bridge module is restarted

There seems to be a little bug that causes an exception in the Designer if the the SQL Bridge module is restarted while a designer is connected.
Version is 7.5.6.
After the module restart, selecting a transaction group in the designer throws the follwing exception:

Hi,

Yes, after the restart, an object that is held in the designer session is no longer valid. Restarting the designer should fix the problem, or you might need to terminate the session from the gateway status page. We’ll fix it soon, though.

Regards,