WR21 Mobile connection fail after upg. from to

I’ve just updated a WR21 from to and now the modem doesn’t connect to celluar network.

In network status> Interfaces>Mobile I get:
Registration Status: ERROR
SIM status: Please ensure correct PIN is configured, save config and reboot.
Signal strength: ERROR

I’ve verified the sim card in a mobile phone and the PIN I correct and internet connection is working fine.
I’ve saved the PIN again repeatedly but error is still the same.
I’ve tried to downgrade the router back to but that didn’t help.
I made a factory reset but even then the error is the same.
Does anyone have any ideas or similar experience?

I actually made a mistake when downgrading the router… Turns out I mixed up the files and only downgraded to…
After downgrading all the way to the mobile interface woke up and the router now connects to cellular network.
However, there seems to be an issue in the newer software versions.

If you haven’t already, I suggest trying the Digi FlashWriter tool, to flash the v5.2.13.4 firmware to the TransPort that way instead (instead of the web interface, assuming that’s how you were doing it).

Note that FlashWriter will set the router to factory default settings, so you may want to either make note of any non-default settings or backup the configuration first (so you can restore it after).


Using Flashwriter worked!
I guess the problem was something in my router and the software updates are OK.
Thanks Jeremym