When you receive this error or response code, then the following 2 issues should be checked:

1)  Are the machine’s date/time/time zone settings accurate? Since the registration process is date/time sensitive, you will want to ensure that the machine’s date/time/time zone settings are accurate in accordance with their location.

or

2)  Is this machine behind a proxy? If so, then your System Admin will need to allow traffic on port 80 for “licensing.productivecomputing.com.” If your System Admin is not easily available, then as a work around you can try to create a hole by opening up a web browser and going to “licensing.productivecomputing.com”.

We can check and see if your machine is even hitting our registration server if you contact us with the machine name. The machine name can be found on a Windows machine by right clicking on “My Computer” selecting “Properties” and navigating to the “Computer Name” tab. The machine name can be found on a Mac by navigating to “System Preferences” and selecting “Sharing”. If your machine is hitting our registration server, then we can rule out option 2.

If all else fails, you can try deleting the registration certificate and try the registration process again.
To clear the plug-in registration certificate, do these steps:

For Windows
1)    Exit your FileMaker application
2)    Go to: C:\Users\<< your user name>>\AppData\Local\PCINC
3)    Look for the folder relating to the plug-in
4)    Delete that folder
5)    Open the demo file and try registering the plug-in

For Mac
1)    Exit your FileMaker application
2)    Go to: ~/Library/Preferences/
3)    Look for the "PCxx.Prefs.plist" file, where xx is the abbreviation for the plug-in
4)    Delete the plist file and restart your machine
5)    Open the demo file and try registering the plug-in