tfur wrote:
I have tried logging in several times (turned off and rebooted), but the MacPro opens to a gray screen. I see the apple symbol and then what appears to be a booting process, but it goes to a blank gray screen and there is nothing to click on.
Don't interrupt it just wait -- and it should eventually go to blue and then bring up the desktop --- just to be sure - restart until the desktop just pops.
You didn't mention the age of your macpro - so you my need to change the little battery that controls the clock.
The thread below lists a number of things that I went through with my late 2008 mac pro -- so you are not alone.
My solution now is to just wait until the system comes up - if its quick I am good to go - if it takes time - I do the multiple restarts.
The freezes were part of a problem generated by the magic mouse -- the long startups have something to do with Unix housekeeping.
https://discussions.apple.com/thread/7518631