We had a Ubiquiti Dream Machine Pro that was stuck on firmware v. 1.12.38. Whenever we tried to run the upgrade from the GUI it looked like things started, but nothing happened. In addition, if we tried to uninstall some of the apps we didn't need such as Talk or Protect, they app would hang on "Uninstalling" forever and wouldn't go away until the unit was rebooted.
The next thing we tried was manually installing the firmware (downloaded from the
Unifi Firmware Site and uploaded to UDM /mnt/data using wget) but would always get a message saying there wasn't enough storage:
ubnt-upgrade: [error] not enough space available for upgrade files (#21)
We also deleted some logs from /mnt/data/log but don't know if that was necessary.
Our solution turned out to be the following:
Uninstall extra Apps from UDM-Pro
unifi-os shell
dpkg -P unifi-protect
dpkg -P unifi-talk
dpkg -P unifi-access
dpkg -P uid-agent
#exit the shell using Ctl-C
reboot
Run the upgrade from command line CLI
ubnt-upgrade /mnt/data/10c9-UDMPRO-2.5.17-4ef0556d8b844aa6ac43c695ef076479.bin