I am also having this issue, must be an error in a recent update, I've ran the tool hub several times recently, as I'm also having issues with the program crashing anytime i run payroll. It hasn't solved any of my issues.
Also, ever since the combine forms option was added, about every 3rd send, it errors out and crashes the program, the only way to sent the emails is to switch if from outlook, to web mail in the preferences.
