Ubuntu 16.04: system program problem detected

This error modal appear repeatedly after a system crash. When a system crash occurs, the kernel attempts to dump debug information into the /var/crash directory. As long as the /var/crash directory has dump files in it, this modal will periodically present itself. So, the continual appearance of this modal does not signify an ongoing issue; rather, that a system crash has occurred at some point in the past. To resolve, simply clear the directory:

sudo rm /var/crash/*

This put an end to this error (until a future system crash, which should be rare).