Your biggest Doh moment...

[Kobal2]

Originally Posted by Soyweiser

Forgetting to upload the turn is also always a big Doh.

Also uploading a turn, then realizing you made a really dumb mistake, or have a blaze of insight into your opponent's plans. So you change your orders in a hurry, and breathe a sigh of relief. Catastrophe averted !

Then you forget to upload the revised turn.
And the exact thing you had taken active steps to prevent happens.