I have a CRS125-24G-1S-2HnD. It is currently at 6.42.1. I've tried updating it, but it won't take the upgrade. I even downloaded the file, uploaded it to the device, rebooted, but it remains at the same OS. What could be wrong?

What does the log say after reboot?

You downloaded the upgrade file for the *correct* architecture that matches this model? https://download.mikrotik.com/routeros/ ... 6.42.6.npk

Yes, that is exactly the version I downloaded, but which the system itself downloaded. Most interesting is the log:

can not install dude-6.39.2: it is not made for mips, but for i386

Ok, I figured it out. The package for Dude was sitting in files and probably installing each time I rebooted all this time. I removed it from Files and now everything is fine.