Can't install Parallels Tools

Hello,

I'm running Parallels 15 on Catalina host and Mountain Lion in the VM.

I tried many things, also have followed these instructions, but I can't get Parallels Tools to work
https://kb.parallels.com/en/112609

I all the time have the yellow triangle warning sign in the Parallels app.



What am I missing?

Thanks!

 

Hi Janne. Please let us know what happens when you click on 'Install Parallels Tools' option. If there are any errors, reply with the screenshot of the error message to check the details.