Thank you for your response. And let me clearly state; You are correct in that I should not have tested this with an actual folder with data that I would have liked to have kept. And so perhaps I can echo your warnings to any users out there; If you are downloading and evaluating the software, do it on data that is either backed up or something you can afford to lose. And make sure you keep track of the password; There was really no excuse for me to pay a little more attention when I was testing it.
With respect to what to do, I understand your point with respect to wanting to let users do background operations to get on with their work. But ultimately, if one person starts an encrypt operation, and then minutes later starts a decrypt operation, you do have to chose to either address it directly by attempting to signal whatever thread of operation somethings going on, or prevent it. This is an edge case, but ultimately if you do nothing that’s just wrong. The fact that it’s an edge case should actually make this easier for you. Just prevent the batch process. Rarely will it be an issue since this probably almost never happens. But when it does, you’ve prevented a possible problem.
But, ultimately it’s up to you. Regardless, there’s no arguing that you respond to everything. Thank you.