Been seeing a fair amount of this error on zcm11.1a agents:

"An error occured because "Method not found: 'Boolean Novell.Zenworks.Zmd.SessionManager.IsDesktopActiva ted(Int32)'.". "


These fixes have been applied to the 11.1a system update and the pre-agen packages. Agent version displays as

ZCM 11.1/11.1a combined fix for "ZENworks Adaptive Agent"
ZCM 11.1/11.1a fix for "File exists" see TID 7009330 and bundles not available for 5 minutes - see TID 7009945
ZCM 11.1/11.1a - "Grant administrator privilege to user during installation" fix - see TID 7009487
ZCM 11.1/11.1a fix for RDP session crash - see TID 7009593
ZCM 11.1/11.1a - ZESM 11.1.166 update