If the issue persists, then we from Fortinet might have to look into this via remote session for Advanced troubleshooting. Kindly open a Support Ticket with supporting details and call our support line.
If you see an error message "All available desktop sources for this desktop are currently busy" when you attempt to login to your desktop, the simple solution is to reset desktop. Use Nerdio Admin Portal. You will need to be a NAP Administrator or ask one to reset desktop for you.
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