Mail can't reply to an email when Safari is Open (El Capitan)
I may have found an curious bug with El Capitan. If both Mail and Safari are open and I try to reply to an email, I get a blank email response window that is inactive -- meaning I can't type anything on this window and I can't close it either. Mail shows a Draft email.
If I close Safari and try again, Reply works normally. However, the only way to get rid of the blank email response created earlier is to close Mail and start it again. Then you can close the open message window and delete the drafts (manually). I've tried opening Safari first, then Mail and vice versa with no success.
I tested this with Chrome and I have no problems replying to email.
Thoughts?
MacBook Pro, OS X El Capitan (10.11.2)