For new devices that will not register after a device pack install, the guide points to a device type mismatch in Phone Configuration and a restart of the CallManager service on the publisher.

Checked 2026-10-02

Vendor
Cisco
Product
Cisco Unified Communications Manager
Subsystem
device firmware
Deployment
on-premises
Region
not restricted
Release range
15 and SUs
Checked
2026-10-02

Sources

Cite this note

APA

WarmTransfer. (2026, October 2). Troubleshooting Cisco IP phones stuck upgrading firmware: source note cucm-phone-firmware-upgrade-troubleshooting-issue-no-register. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-phone-firmware-upgrade-troubleshooting-issue-no-register

BibTeX

@misc{warmtransfer-claim-cucm-phone-firmware-upgrade-troubleshooting-issue-no-register,
  title  = {Troubleshooting Cisco IP phones stuck upgrading firmware: source note cucm-phone-firmware-upgrade-troubleshooting-issue-no-register},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/cucm-phone-firmware-upgrade-troubleshooting-issue-no-register},
  note   = {Source note cucm-phone-firmware-upgrade-troubleshooting-issue-no-register, checked 2026-10-02}
}

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