If you are using auto/custom generated certificates and get the following error:
Your remote desktop connection failed because the remote computer cannot be authenticated
The remote computer could not be authenticated due to problems with its security certificate. It may be unsafe to proceed.
Requested remote computer:
Name in the certificate from the remote computer
The following errors were encountered while validating the remote computer’s certificate:
The server name on the certificate is incorrect.
You can still get in by doing the following:
1. Open TS Remote App Manager
2. Click ‘Change’ next to ‘RDP Settings’
3. Select the ‘Custom RDP Settings’ tab
4. Add the text ‘authentication level:i:2’ to the Custom RDP Settings dialog
5. Add your Remote Apps and they should now work externally through TS Web
6. Add your certificate to the RDP-Tcp connections in Terminal Services Configuration (tsconfig.msc)
PS! Make sure you remove and re-add the Remote Apps you need.