Mail is not working after upgrade to El Capitan
I just upgraded my system - MacBook Pro (13-inch, Mid 2012) 2.5 GHz Intel Core i5 SSD 500GB Drive running Mavericks to the El Capitan version 10.11.6 (15G1004).
Now -
1. MacMail is not working after upgrade - Menu bar shows, no window visible.
2. MacMessages is not working - Menu Bar shows, no window visible.
3. System will sometimes "Crash" or will "Restart" randomly.
Does anyone have advice to solve these problems?
MacBook Pro (13-inch Mid 2012), iOS 10, 10.11.6 (15G1004)