[2021] Data error in launcher after update (solved)

So it was an anti-virus problem?

Which one do you use please?  

I now have reports of this with Avast antivirus only, except just 1 report on AVG. Putting the launcher in all its exceptions lists seems to be fixing it reliably.

I also have one report that opting into the beta of the next launcher version 2022.1 helped.  

Notanoctopus said: C:\Users\\AppData\Local\Programs\Paradox Interactive\launcher-v2.2020.16\Paradox Launcher.exe

But that is a really old version of the launcher, current is 2021.10.1 . Probably if you'd added that version of the launcher to the Avast exceptions list, that would have helped too.