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macrumors regular
Original poster
May 15, 2014

Just found out that the Apple TV app in Catalina 10.15.2 in my MacBook Pro w/Touch Bar just won't play movie when I connect an external display (LG 27UK850) thru BlackMagic eGPU. The movie will play for 0.1 second and then it quits like the TV app crashes, but actually it's just the video playing window that closes itself, not the TV app.

I tried to connect the display directly thru the HDMI/USB-C cable, or just use the MacBook built-in display, then the movie can be played without any issue.

So I almost can safely conclude that the eGPU is stopping me from watching videos in Apple TV app in my MBP.

Just checked the system log and the error messages are all like this:
nw_endpoint_flow_copy_multipath_subflow_counts Called on non-Multipath connection

Anybody has the same issue?


macrumors regular
Apr 9, 2011
Did you ever find a solution? I am not having the exact same issue but it seems similar. Trying to stream content Apple TV in Catalina on my (unsupported) Mac Pro 5,1 is not working. It plays for between 1 and 15 seconds then stops. Local content seems to play fine. doesn't seem to matter with device (HP monitor or Cinema display) it is going to.


macrumors newbie
Jan 18, 2021
Same problem here. Since about Jan 10 (maybe due to an upgrade to BigSur 11.1) MacOs App TV won't play any movies or shows on an external projector while everything else works (including amazon prime where I ended up renting the movie...).
It worked from December to Jan and it still works on an older MacBook (I am not sure which version of OS).

Somebody should tell Apple.


macrumors newbie
Jan 31, 2021
Probably a stupid question, but I'm trying to see if my issue is same/similar; do you experience this problem playing video from in Safari? If so, what are your results when using Chrome or the Microsoft Edge browser?

For me, videos spawned to external monitors stop playing after 5-10 seconds when using the Apple TV app or from using Safari, but work fine with the Chromium based browsers. Same experience playing video from Amazon Prime.

Just curious... thank you in advance!
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