With Symantec Endpoint Protection (SEP) 12.1 RU5 installed, the list of available media files in Avid Media Composer takes a significantly longer amount of time to appear. During this time, Avid Media Composer appears to be unresponsive. This happens in environments where media files are loaded by inserting Sony XDCAM Drives into the USB reader while the application is open.
This issue is not observed when running older versions of SEP.
This appears to be caused by the Auto-Protect Read Cache added in SEP 12.1 RU5. The caching of files increases the amount of data read by SEP before scanning, leading to the delay.
This issue is resolved in SEP 12.1 RU6 MP7 and SEP 14 MP1.