I'm on mac sierra 10.12.6 and pro tools ultimate 2018.4
I get the same lag and beach balling properties everyone else in this thread gets however, there is a fix. If I make sure I'm on the internet and quictime_OPServer can access it, then it's able to seek and find what it's looking for and the lag goes away immediately. Also, I will not have a problem for the rest of the time that pro tools is open, even if I don't have internet access. Now, if I restart and open pro tools and don't have internet access, the lag problem comes back. So, we are currently just trying to figure out a way for to not have quicktime_OPServer look yet, still able to play video files. If you quit the process you won't be able to play .mov files.
More to follow hopefully.
