I did, they answered with some links, have a look! 

dg

Okay, thanks for your reply - well fixed apparently, my TO works stable, no complains. Have fun working! 

dg

@All & Vladyslav: I use the tip of the above link how to share the data across computers more or less easily:

[...Just expand all nodes, save the view through Ctrl-S and you will be able to drag hierarchies from this file to some other Tabs Outliner instance, or just use this file on its own....] - Note: important to save as a hole website not just HTML. So, don't change the default.

I save the expanded (important) tree onto a memory stick and copy the subtrees one by one  (still the lack of multichoice) to other current session trees on other devices. Until now - unfortunately - it is not possible to copy just the hole session tree. As soon as it would be possible to have more than just one 'current session' this workaround would be very handy and a quick solution. 

I would copy the hole freshest tree by drag&drop from the opened file to the TO-Window and delete the old 'current tree' (the one which was already inside the TO-Window, becoming obsolete at the same moment, when I paste the fresh one aside). Of course before starting new sessions on that computer, but even if later, I would just have to take care to move the new sessions subfolders to my fresh tree, before deleting. 

This would be more than a workaround, I would have my current data in my pocket on a stick instead of in a cloud, transfering at ease. But will have to save on a stick or network (or dropbox, google drive, cloud)... again and again, before I leave any computer. So for me a cloud solution is at best, because I change a lot, but I would like to have the choice. 

One may answer to put everythin once in a group folder instead of copying subfolders one by one, but the group behaviour properties will inherit on everything then and this is probably not desired. As well to get them out of the group folder would imply the same, drag and drop one by one, due to the lack of a multichoice. 

So my conclusion or suggestion concerning the major priority is or to add the multiple 'current session' ability or multichoice or both. Suitable to work then in an accurate manner across computers, while waiting for an implemented cloud solution, which is probably more work to realize. 

But I am already happy as well about what you have achieved until now, Vlady! Thanks again!

dg

Above I meant the mess with tabs prior to TabsOutliner (TO), not with how to use it - to prevent misssunderstandings, the documentation is very good. Further there is a misspelling, I meant TO not OT, sorry. 

dg