03/26/2020 8 People found this article helpful 457,741 Views
HTML5 RDP bookmark fails with error: Connection Closed! Error(TypeError: a.readCertHex is not a function)
HTML5 RDP bookmark is configured to access a terminal server. It fails to connect with error "Connection Closed! Error(TypeError: a.readCertHex is not a function)"
The same bookmark works with Java or ActiveX.
Resolution: It is an issue with the encryption setting on the Server which needs to be changed.
Go to RDP-TCP properties:
Check if the setting is set to low encryption
Negotiate and encryption level to Client Compatible security
Save the changes and the bookmark should work.