I was just experience this along with some other broken functionality - It seemed like after a update to the vm.. My Forticlient VPN was not working also.. From a reddit post (https://www.reddit.com/r/fortinet/comments/lpr8ux/anyone_having_javascript_error_on_main_process/) I found link to reinstall C++ 

https://docs.microsoft.com/en-US/cpp/windows/latest-supported-vc-redist?view=msvc-170 "Visual Studio 2015, 2017, 2019, and 2022"

After I installed the C++ redist and restart the Forticlient VPN was working and copy and paste between virtual machines was working.