The Same config also at my side. DC, Exchange and the panel on the same server - server 2016 with Exchange 2016

I updated the version to 1.2.1 and now it deletes users!

Have the same problem, Win 2012 R2, Exch 2016, SolidCP 1.2.1

Any workaround to delete user manually from Database?

PS have also deleted user from Active Directory

1. try to connect to the server via RDP and then access the panel locally AKA 127.0.0.1 and then try to delete the user. This should bypass any timeouts that you have over the internet.
2. You can delete the user in the DB and then in the AD. But you should wait that Marco will answer you from which tables you should delete.

Tried connected from inside server and it finally worked

KUDOS Eran