I am unable to Netboot Late 2015 27" iMACs. We are using the 10.11 version of the netboot image. We can Netboot all other models that we have except this particular model. When we attempt to Netboot we get this prohibitory symbol.
Do we need to upgrade the Netboot image for this model or is there something else that needs to be done?
Thank you in advance.
Solved! Go to Solution.
Check what build of 10.11 you are using. The iMac (Late 2015) models use 10.11 build 15A4310, which is unique to that model. If you update your NetBoot image to 10.11.1 or later, it should work on all current Mac hardware.