[EduardMe]

I recommend to switch to CloudKit sync and check if you don't have changed the file extension in the preferences.

[darkpicnic]

I changed to CloudKit and changed the extension as well to ".md". I was able to add a calendar event once or twice, then the same issue came up again where it could not add event and asked me to email support. I've deleted the app and reinstalled a few times. Anything else I can try?

[EduardMe]

I'm looking into the event creation problem. Restarting should usually help at least temporarily.

[chrisked]

Any plans to implement Dropbox sync? iCloud or CloudKit is a no go for me.

[EduardMe]

Dropbox is an option already, but it's not as stable and has problems.