When trying startup Mac OS 10.11 (.5 I think) via the option key to select bootcamp partitio, the startup manager doesnt load with the available drives. After the startup chime the screen just remains blank and nothing further happens. The startup just freezes. I have to force shut down by holding down the power key on my Mac Pro.
Any ideas what could cause this, and how to fix it?
Does System Preferences -> Startup Disk -> Bootcamp work correctly?
Yes it does, so I was able to get into Bootcamp/Windows, but then couldnt get back as the Option key on startup doesnt work.
I then discovered in Bootcamp in Windows that there is also an option to change the startup disk (i didn't know that could be done in Windows also), so was able to get back to Mac OS that way.
But still doesnt explain why Option key startup fails.
cheers.
Are you using rEFInd or rEFIt?
Please run the following two procedures
Reset the System Management Controller (SMC) on your Mac - Apple Support
How to Reset NVRAM on your Mac - Apple Support
and re-test.
Startup Manager via option key fails
