Failed to create KVP sessions string. Error Code 0x8007007A

I got a lot of "Failed to create KVP sessions string. Error Code 0x8007007A" errors on my RDS (Session collection) on Windows Server 2012 R2.

I think this problem is related with roaming user profiles which are not properly synchronised (only 4-5 users affected on 100 total users).

Second error happening : "remote desktop services has taken too long to load the user configuration"

Are roaming user profiles well supported on RDS ? Anybody knew what's happening ?

Our antivirus, Kaspersky For Windows File Servers have exceptions to exclude user profiles on domain controller.