Movie will not export - iPhone XS Max

I have a similar issue.

4K video coming from my Nikon w300

iPhone XS Max 256GB

Space left 208GB

Estimated size of exported video 1.2GB

Time of clip 4:27 min

Rush v 1.1.6 (468)

I managed to actually get to the point of exporting the video once but it crashed when trying to choose the starting frame. Also it didn’t upload in the 4K format to YouTube that the project settings were set to but that could be due to the crash. After that I had no luck to even get close to exporting a video the app just crashes when using the iPhone XS Max.

I opened the project on my iPad Pro but when trying to export I get a warning that media is missing. It doesn’t tell you what media though.

So I finally got to export the video from my iPad Pro. Even though I get warnings that there is media missing I can’t see any difference also the estimated size is larger, 2GB, without doing any changes except removing the music. I exported it to YouTube and everything went smooth but it took about 30 min for a 4:27 min clip but it’s 4K so..., I can confirm that it’s 4k on YouTube. I’m not really sure what’s going on here but maybe the app isn’t adapted enough to perform well on iPhone X and XS? I’ve seen this with other video editing apps. The iPhone gets really hot whereas the iPad doesn’t so I’d guess it needs tweaking. For me the copy that goes to my camera roll is 4K. I verified it by downloading the file from my camera roll to my w10 pc and then checked the preferences of the clip.

Hope to get some feedback on this soon!

Mine worked after restarting the phone.

How long is the movie? Was it shot on the iPhone in HEVC?

Have you tried restarting the phone?

MtD

Just to clarify... Are you trying to export videos From Rush to the Photo Library?