OK, I'll assume that you are on the 200Gb tariff for iCloud. I have quite a collection of movies, very few, if any, are more than 1 Gb in file size. For the greater part, my movies are in .MOV format. Some are in .m4v format. Apple's systems are only geared up to certain movie formats. https://support.apple.com/en-gb/guide/motion/motn1252ada3/mac although I doubt that should affect why your video is being declined.
I'm hoping this will resolve your issue:
How to Upload Videos from iPhone to iCloud?
If you have videos on your iPhone, then you can transfer videos from iPhone to iCloud easily. There is a typical way to upload videos from iPhone to iCloud i.e automatically sync videos from your iPhone to iCloud. You need your Apple ID and password to log in the iCloud. First, connect your iPhone to Wi-Fi network. To do this, go to 'Settings' and tap 'WiFi' button and then move slider from left to right to turn ON 'Wi-Fi'. You can sync photos, videos, books, apps, music and much more from multiple iOS devices (like iPhone, iPad, iPod touch) to iCloud.
Here are the steps to Upload Videos from iPhone to iCloud:
- Open iPhone.
- Tap "Settings" on your iPhone.
- Tap "Network" button to connect iPhone to Wi-Fi.
- Tap "Wi-Fi" button.
- Move the slider from left to right to turn ON "Wi-Fi".
- Go to https://www.icloud.com/ & sign in to your account. If you don't have an account, then create one.
- Tap "Settings" on your iPhone.
- Select "iCloud" option.
- A "Storage & Backup" window opens up.
- Move the slider from left to right to turn ON "Back Up to iCloud".
- Tap "Back Up Now" button to upload videos from iPhone to iCloud.
- This is how you can upload videos from iPhone to iCloud.
Quick Tip to ensure your videos never go missing
Videos are precious memories and all of us never want to ever lose them to hard disk crashes or missing drives. PicBackMan is the easiest and simplest way to keep your videos safely backed up in one or more online accounts. Simply download PicBackMan (it's free!), register your account, connect to your online store and tell PicBackMan where your videos are - PicBackMan does the rest, automatically. It bulk uploads all videos and keeps looking for new ones and uploads those too. You don't have to ever touch it.
