Media Composer 8.5.1 had a bug that would not allow HDV Capture via firewire. I was told to wait until 8.5.2 and the bug would be fixed. I now have 8.5.2 and the Video Button in the Capture Window is still ghosted.
I can capture DVCam via a Sony DSR1800.
I cannot capture HDV via a Sony HVR-Z7U. I have used the Z7 for years with great success.
I can revert to older Avid versions however I can not back track the Mac OS
MEDIA COMPOSER 8.5.2
OS X Yosemite Version 10.10.5
Mac Pro (Late 2013)
Processor: 3.5 GHz 6-Core Intel Xeon E
Memory: 32 GB 1866 MHz DDR3 ECC