Verify that the DZ Registration window's Site Name matches exactly with the Site Name listed with the registration keys we generated.
Verify that the DZ Registration window shows the correct version of Microsoft Dynamics GP .
Verify that the registration keys are for the build number shown in the DZ Registration window.
Ensure that every computer has the same DynamicZip build number installed.
Verify that the registration keys are for the user count1) shown in the DZ Registration window.
If the registration keys have been accepted, and the invalid registration key message still occurs, it may not be DynamicZip that is generating the error message. Try disabling DynamicZip to see if the error message goes away.