Video goes black after 5 seconds editing. Sony Vegas 13

Hi, yesterday I rendered a video and the last 2 minutes had image but it was like 1 frame per second. It was 'jumping' (the first 4 minutes were perfect).
I closed Vegas and reopened the project and after loading, I can see everything fine, but after 5 seconds all the previews go to black.
Of course I tried rendering and it's black.
Tried disabling gpu acceleration and it's black.
I copied every file to another computer and it's black.
I'm using .mov files recorded on Iphone 6S.
The sound is fine. Pictures can bee seen fine. I didn't install anything in the past days and I've used it just fine hours before this problem.
MediaINfo says 1920*10880 29.970 fps AVC High@L4 CABAC / Ref Frames 15.5mb/s MPEG-4 (QuickTime)

Any ideas?

edit: I've used videos recorded from this phone before no problem.