Uploading videos originating from an IPhone 7

Ok. I have uploaded 4 different videos all taken within days of each other (with iPhone 7 & imported to PC) yet Shotcut will only recognize 2 of them… conicdentially the same 2 I have uploaded to my YouTube Channel… and I can find NO OTHER difference between these videos ??? All shot and uploaded under the same format. Why does Shotcut crash except for the same 2 videos taken amongst others !!! Thanks

Perhaps the header or meta data inside the troublesome files are corrupted.
transcode them in Handbrake first, this may repair any issues.

BTW: phone to computer = Download.

Upload generally refers to the Internet (website/facebook/youtube etc)