Allan, there is not any official documentation on these CTI codes error that you get on Finesse Desktop. That being said, please refer to the below Release Notes and make sure that there is no unsupported configuration being done either on UCCX or for the agents that most of the times is the issue causing this failure message to come:
http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/crs/express_10_6/release/docs/UCCX_BK_UC733F42_00_uccx-release-notes-106/UCCX_BK_UC733F42_00_uccc-release-notes-106_chapter_00.html
Regards
Deepak