Hi
I am running version 15.41 (171205) of Outlook on Mac High Sierra 10.13.2, and have disappearing outlook tasks. Some of them seem to appear but when you edit them they disappear.
Any newly created tasks due today appear briefly and then disappear
Tasks due in the past / overdue appear but if you edit they disappear
[screenshot removed]
New tasks due in the future seem to be able to be created ok
Tasks that already existed and were due in the future have disappeared.
I have tried pasting an old version of the tasks folder saved through time machine, but the problem is the same.
I also have several blank tasks (which have categories) which I can't edit - these may correspond to some tasks due in the future.
See screenshot below: