Ask the following:

1. Is the used version of the print server compatible with the version of Crystal Reports embedded in the X3 client, with the Operating System of the Server?
2. What is the context (are all reports printing, only specific report(s) failing, are all users printing or only specific user(s) failing to print)?
3. Did the issue appear recently/gradually or after any update of one of the X3 components?
4. Any antivirus or firewall blocking connection to the print server?
5. Is the print server properly configured in the configuration console?

Look out for: 

1. Destination settings
2. ODBC settings
3. Xml files in \<print server name>\srvedt\config
4. Print server debug logs
5. Print server in console mode
6. SQL tracing log

Get printing again and enjoy Sage X3 experience, if you still cannot resolve the issue you can send all the logs and other elements collected to Support.