The issue is that the Fix version is not added automatically on Sprint creation for some projects.
So I cannot select Fix version anymore for some projects though I have few sprints created.
Note that the items are visible on TestSprintIS2 sprint board, but they are not visible when I select other sprints.
Due to this I also don't see how the item related with sprint and I cannot move item to another sprint.
Fix version field looks by the same way as for other project where it works as expected, and I didn't find any configuration to create Fix version value on sprint creation.
We are using the following version of YouTrack: