I'm having this exact same issue.  Worked fine before.  Disabled virus protection, also allowed pass-through on the protection, installed, reinstalled. It will only let me play if I delete the game and reinstall plarium play.  If I close it out, it will not reopen and I have to repeat reinstall.

I just ran a trouble shooter through the properties and it's saying that the Plarium play program is not compatible.  I'm running windows 8

Yesterday I had the same problem: impossible to launch PlariumPlay suddenly (after 2 years )

I have tried multiple installs and reinstall with no success...I even updated my windows from 10 to 11 :)

finally I found after 4 hours of research : the origin of the problem was on the library Microsoft .NET SDK 6.0.101, i uninstalled that and install the version Microsoft .NET SDK 6.0.407, restarted my computer and PlariumPlay started normally..

I don't know why it suddenly became a problem, maybe a security update..

thank you for your input. It worked for me, i had the same issue. 👍 much more helpful than any of these "moderators" running around in the forum doing all shorts of nothing .

Yes, they definitely are! 

I'm glad you updated your Microsoft Library and that helped. I'm certainly not a Microsoft Tech to be able to actually be helpful with Windows issues like this. 

Although to be fair to my fellow mod:

i

It seems he was able to figure out the fix. 😎 

Welp...after spending two days taking emergency coding classes to understand what the hell I was suppose to be doing and relentlessly attacking the command prompt, I finally downloaded the shell and the right sdk file and it finally worked.  I ended up downloading and trying various options.

So bizzare.  

dont know why but  that net sdk realy helped it :D

Thank you, this worked for me, no update happened but Plarium Play stopped working so I have no idea what causes that.