If you don't see OneDrive among the locations, there are two possibilities:
...button in the file selection dialog, then
Edit, and make sure that OneDrive is turned on.
“Failed to open file. Reason: The requested operation couldn't be completed because the feature is not supported." This error message might appear if your network connection is unstable or restricted by a firewall. Switching to another network should resolve the issue.
When you try to add a database from OneDrive for Business, the file seems to disappear when you tap it. No worries, the database is still there — but your corporate IT policy does not allow accessing it from other apps, such as KeePassium. You can use the workaround described above.
If synchronization stopped working after you have upgraded to iOS 13, remove your database from KeePassium, reinstall the OneDrive app, then add the database again.
If you encounter any other issues with OneDrive, please let us know.
Last Updated: 2019-10-13