Raspberry Pi stuck on Starting kernal

I just installed Ubuntu Mate on Raspberry Pi 3 B+ and it worked fine on first boot.
I then did an apt update and upgrade and now I'm stuck on this screen.

Any ideas?
I'm assuming it's ok to upgrade the Raspberry version of Mate?

For anyone else that's having this issue I fixed it by following a solution by Andreas.

1 Put the SD card in another computer
2. open the config.txt file and search for device_tree_address
3. change the number next to it to 0x02008000 so it looks like this:

To be honest I'm not 100% sure what it does but it works and now I'm booting up fine again :slight_smile: