Workers stop improving!

[OldMansWar]

I complete a turn. "Next Turn" is up and I click on it...but suddenly "Unit needs orders" ===> a worker that had been ordered to do an improvement or road is standing still!
What gives? Are they on a coffee break?
I RE-ORDER them to their task, click on Next Turn and I finally get my next turn.
What's the problem?

 

[joncnunn]

Workers auto wake up from working if an enemy unit comes too close (e.g. barb unit or any unit from a player you are at war with.)