Matlab inoperably slow on Mac

When it opens, it will work for a few seconds and I can get a standard bench time. Usually by the time I try to run bench for a second time, it becomes incredibly slow and the fans start running. The bench freezes before I can even finish it. It worked fine for months before this started to happen. Any ideas on how this can be fixed?

Mac with OS X Yosemite running Matlab R2014b

[mkrum]

I just got this error trying to run bench after running it successfully.

Error using matlab.graphics.primitive.Text/set Invalid or deleted object.

Error in bench (line 69) set(task,'string','LU')

[Harrison Bachrach]

I have a similar performance issue for both R2014 and R2015a. R2013 worked fine!