I had a similar problem with the default version of gscan2pdf available from the default Ubuntu 16.04 repositories. I would scan, but the error message would arrive after the scan was completed.
gscan2pdf version 1.3.8.
I then installed the following PPA to get the latest version, 1.8.3:
I had a similar problem with the default version of gscan2pdf available from the default Ubuntu 16.04 repositories. I would scan, but the error message would arrive after the scan was completed.
gscan2pdf version 1.3.8.
I then installed the following PPA to get the latest version, 1.8.3:
sudo add-apt-repository --yes ppa:jeffreyratc liffe/ppa
The problem was gone. I suggest you upgrade gscan2pdf to the latest and report your findings. We might be able to close this ticket.