Ver 9.0 - [810215] Method MakeDecision() has been disabled and cannot be run

Hi people.

We are in process of migration from ver 8.1.5 to ver 9.0 LTS (+CU1) and met a strange error in ver. 9.0 LTS

Process VI_Attestation_AttestationCase_AutoRemoveMemberships fails with error message:

[810222] Error running script 'VI_AttestationCase_RemoveMembership'.
[810215] Method MakeDecision(VI.DB.Entities.ISession, VI.DB.Entities.IEntity, System.String, System.Boolean, System.String, System.String, System.Int32, System.Threading.CancellationToken) has been disabled and cannot be run.

Never saw such errors in ver 8.1.5.

Unfortunately, the error message doesn't say much about the root cause of problem. "Method MakeDecision() has been disabled..."   Was it disabled somehow by us?