The Meridian Full Client is not compatible with European Cloud tenants. The Meridian Full client connects and authenticates to the American .net domain instead of the European .eu domain. This causes errors for customers download and run the Meridian Full Client, when authenticating with the .net domain. Resolution and workaround is known (see attachment), but not implemented in the download version of the Meridian Full Client.
This part is addressed in our 2019 Q4 release. Existing tenant updates are being scheduled in this quarter.