What is the issue?
Error 27 means, that a Single User License is used via Terminal Server. This is blocked by the licensing system.
How to fix it?
Case A: There shall be basic access via terminal server
If you basically want to use axesPDF software via terminal server, you have to buy a Concurrent User License instead of a Single User License.
Case B: Only activation shall be possible via remote access
An activation of axesPDF software on a client is possible via remote access. Of course, the software is then only on the corresponding client activated.
But: You will not be able to check the activation via remote access. Because in such cases you allways get the error message "Error 27".
The activation of a Single User License can only be checked on the client itself. If the activation was successful, you can see the correct expiration date instead of error 27 in the activation window.