5a693e87_Plus__known_issues____RealVNC___Workaround
[ID] 401 [Description] An encrypted connection cannot be established if the Common Name (CN) field in a TLS certificate contains characters such as ® or ™. [Status] Under consideration. [Workaround] 
Avoid non-standard characters.
VNC® Viewer Plus (known issues) - RealVNC®
Workaround