"Unsupported Project File Format" when sycing

I’m trying to sync a previous project to my iPad. I’ve updated the desktop version (windows) to the most recent version and re-saved the project to dropbox. The project shows up in the iOs app but when I open it it says “the .scriv project is of an older format that cannot be opened on mobile devices. Please update it in the latest version of Scrivener for Mac or Windows.” I’m not really sure how to do this/what this means since everything is up to date and the project said it updated to the new file format when I re-opened it after updating the desktop version.

You updated Windows Scrivener, opened the project, saved it in the Dropbox folder, but iOS Scrivener can’t open it?

Is it this specific project or all projects?

If only this project, there has been reports of web links in old projects creating problems for the iOS Scrivener.

Check out this thread here, there now seems to be multiple fixes though removing weblinks in files fixed it for me:
https://forum.literatureandlatte.com/t/file-not-compatible-unsupported-project-file-format/33968/1

I had the same issue even after going into all my older projects and updating to the newer format. I read in another post, which I cannot find at the moment, in another thread, that what worked for them was making a change, any change, adding a period or a letter to the Desktop file. Then, when syncing on iOS it opened just fine. The same worked for me…