[Forums] Invalid Aggregate - Aggregate cannot join data from multiple databases

Hi All,

I have an espace that is working ok at V7 (see top image)
I have updated to V9 and I get the following error:

"Invalid Aggregate
The 'Name' Aggregate cannot join data from multiple databases. Change it to only use entities from a single database." (see btm image)

I understand what the message is saying but I don't understand why. The espace references a foreign entity from a legacy system that is still live and therefore cannot be changed.

Is this a bug... do you have to reference foreign entities in a different way in the newer platform...? basically the old simple query worked fine... the new aggregates function fails...
please help..!!

Thanks Gary