P: Notifications shouldn't stop all running tasks

I asked the system to move some files and generate a bunch of previews before going to bed.  A couple of minutes in, Lightroom couldn't find one of the files, so it presented a messagebox letting me know.  

This notification box, until you click OK, seems to pause all running tasks... so I didn't get any of the previews generated overnight.  I was hoping to have a more productive day that doesn't involve waiting for previews.

1. Seems unnecessary to prevent a preview generation task if that task doesn't have an exception.

2. It would have been nice if the task continued to move the many thousands of files that weren't in error, still present the warning that one or more files couldn't be found.