The error can be caused by many issues. If we are able to login it would be the fastest way to find/fix the issue, provide credentials here, if possible.

If login is not possible, use the link above to send the PDF to us for testing. Also include a screenshots of;
– The complete field map layout.
– The PRO2PDF shortcode (On Submit Message Box or Email Action Message).
– The SETTINGS tab and the UNDER THE HOOD tab.

To troubleshoot by forum messages, provide the screenshots requested above, as well as answers to the following to begin the process;
– Has any merge with any form worked on your server?
– Are you able to Export a merged form from the plugin’s EXPORT tab?
– How many fields are in the merge?
– Are there any signature or image fields in the merge?
– Try creating a merge with only one field and test, if it works add additional fields and test until you find the issue causing field and let us know.

We remain at your service.