Why do the iOS and Mac versions save as different file formats and are there any issues caused by this?

I have OO5 for mac and OmniOutliner 2 for iOS. When I create a file on iOS, it saves in the oo3 format and when I open on the desktop it asks me to convert it. Why is this? Are there plans to harmonize the file types or am I just missing something in the settings? Will this possibly cause problems with my outlines?

OmniOutliner 2 for iOS is designed to work with OmniOutliner 4 for Mac. OmniOutliner 3 for iOS is currently under development which will be the iOS partner to v5 and include an Essentials edition. We added the ability for iOS v2 to open and edit the new OmniOutliner 5 format but it does not support any of the new features introduced in v5, most notably– filters. If we switched the default format to the new ooutline format, those still using v4 or v3 would not be able to open the files nor would it be of any benefit on iOS.

There are no issues with using v2 and v5 together aside from being asked to convert to the new file format which is optional.

Well, I can’t open a document modified in OO for IOS (v2) from OO on my Mac (v5) – and I’m not “being asked to convert”. Instead, I’m only told that “The document “xxx.ooutline” could not be opened. The data is not in the correct format.” Please advise.

You’re unable to open this file on your Mac? But it does still open on iOS? Would you be wiling to send us a copy of this file? It’s possible there’s an XML encoding issue though we’ve fixed the situations we’re aware of. You could also try exporting from iOS to the “OmniOutliner 3 Document” format and see if that works.

Thanks for a speedy reply. I tried to open the document from my other Mac (identical configuration), and it works flawlessly. It could have been a system problem on the first Mac, for Endnote also acted up, until I shut it down and restarted.
Anyway, the v3 trick also worked.