My iOS Dropbox app won't play one of my videos; it says the file extension's missing.

Is it a video type that can be played on an iPhone? What is the file's extension?

Hi, Jan here from the iOS team, +1 on the question about the video extension. The error about wrong extension is a last resort when we generally fail to play it and detect it might be something else basing on the file content. So I think it has to somehow fail to play in the first place.

Hi Jan, I have the same issue on my iPhone, with .mp4 files in a folder that I've made available offline. All files show as downloaded with a green checkmark. When I'm online, I can open and view the files. But when I go to flight mode and restart the Dropbox app, I get the "File missing extension" error. When I click "Rename", the name already ends with ".mp4".

So it seems like a bug in the app.

Hi there AC3EE963B1BF - sorry to hear about this.

Can you please let us know your device's exact OS version, and the version of the Dropbox app installed there?

Does this affect only mp4 files or other file types as well?

A screenshot of the exact error you're getting would also help!

Hi Walter, thanks for the prompt reply.

I'm on iOS 18.1 and was using Dropbox 432.2.4 when I got the error about the missing file extension. I've since updated the Dropbox app via the App Store (to the newest version available today), and now the error has changed.  Please see the screenshot attached.

I'm confused as to why I need to be online to view a file that's literally "available offline"? I want to watch these videos on an airplane, for example.

I haven't seen the error for file types other than ".mp4"…but I haven't tried many. It seems to be working correctly for smaller things like ".txt" and ".md", and .jpg/.png files.

Thanks for the screenshot and the additional info, AC3EE963B1BF.

Have you added your Dropbox files to your Files app perhaps? And if so, are you able to view the videos from there?

How about if you save them to your device?

Hi AC3EE963B1BF, just checking to see if you saw our last reply.

If you're still experiencing the issue with your files not playing on your iOS device, could you assist us further with the information we requested in our last post?

Otherwise, if you resolved this matter, please let us know what worked for you!