I have read a few confirmations about this on the Adobe board.
Older Mac (2009) running 10.11.6 (upgrade to 10.12 not possible). QuadCore with 8GB Ram.
I tried bringing in some clips that were shot with an EX3. These are 1440x1080 60i, not a format I really shoot anymore.
Using "Media Browser" some of the clips look normal, and most just show the Quicktime MOV logo (those come in as just audio).