Source note · Troubleshooting Cisco IP phones stuck upgrading firmware
COP files with k3 in the name are signed with keys used by Unified CM 10.0.1 and later; to install one on an older release, Cisco says to check the ciscocm.version3-keys.cop.sgn README first, and a missing key produces 'The selected file is not valid'.
Checked 2026-10-02
- Vendor
- Cisco
- Product
- Cisco Unified Communications Manager
- Subsystem
- device firmware
- Deployment
- on-premises
- Region
- not restricted
- Release range
- pre-10.0.1 clusters
- Checked
- 2026-10-02
Sources
- Cisco IP Phone 8800 Series Release Notes for Firmware Release 12.0(1) — Cisco Systems · tier 2 current vendor documentation · Cisco Unified Communication Manager Public Keys
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting Cisco IP phones stuck upgrading firmware: source note cucm-phone-firmware-upgrade-troubleshooting-k3-keys-pre10. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-phone-firmware-upgrade-troubleshooting-k3-keys-pre10
BibTeX
@misc{warmtransfer-claim-cucm-phone-firmware-upgrade-troubleshooting-k3-keys-pre10,
title = {Troubleshooting Cisco IP phones stuck upgrading firmware: source note cucm-phone-firmware-upgrade-troubleshooting-k3-keys-pre10},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-phone-firmware-upgrade-troubleshooting-k3-keys-pre10},
note = {Source note cucm-phone-firmware-upgrade-troubleshooting-k3-keys-pre10, checked 2026-10-02}
}