If you get the above error message there’s a quick fix / solution to it!

“A critical error occurred, the application will be terminated. Please notify us about the error in our support forum. Failed to convert string nan to float.”

Will be displayed in an error box.

How to fix it

This error message is related to your “favorites” settings inside teamspeak.
So you’ll have to delete and reinstall the whole Teamspeak program in order to resolve this problem.

1. Download first the newest version of Teamspeak here.
2. Then go to settings panel and start the deinstallation of your Teamspeak.
3. Don’t forget to click “remove my config file” when you deinstall Teamspeak.
4. Then just reinstall it with the newest version and the error should be solved.
5. Don’t edit your favorites settings because this might mess up Teamspeak again.

Another way to fix this error

This method is little bit harder because you will have to remove the configs yourself.
I didn’t try this method but it should be working as well as the whole reinstall method described above.

It’s also possible, that your config file is inside the teamspeak installation folder unlike shown in the following video.