Upon clicking the Submit button in the SDForm dialog window, it may occur that error number 7840 can appear.
Cause:
In one case, the SecureDoc installation package had been defined to automatically add additional Users to each machine AND in that particular situation, those additional users were marked to use Token authentication but did not have a Certificate associated with the User Account in SES.
Resolution:
Cancel the installation
Remove the problematic users from the Installation Package definition
Re-generate the package and then re-try the installation
Alternatively
Import into the specific user accounts the necessary Certificates
Re-generate the package and then re-try the installation