battlefield-4
In Battlefield 4 in commander mode I recently had a game where a large area was blocked from scanning for virtually the whole map (it started about mid game of a 3000 ticket game and then didn't end and didn't move an inch, or even a pixel for over 10 mins)
It was a very long match and the enemy commander used EMP UAV's in other places, so it wasn't that.
Was it a bug? A deployable? How can I counter this?
Those are your "Field Upgrades" you can unlock and earn many different upgrades which you can switch out like a kit. Each one has 4 levels of perks that they give. Each bar is a new perk. As you fill up your bar, you unlock more perks. You'll see in that screenshot they have unlocked 1 of 4 of their perks currently.
Your best bet is to choose perks that align with your play style and stick to your squad. By getting squad points you unlock them all pretty fast in a game. Also you should always have (preferably your squad leader) in the back where they likely will not be killed. Your squad leader should also make sure they are issuing orders on points to get tons of bonus points.
The possible Field Upgrades are:
All taken from here where you can also get more information!
It is done by working with your squads. Squad points are made when healing a squad mate, being a spawn point, capping a designated flag, etc.
If you lone wolf, your squad will take more time unlocking them. Same goes if your squad leader does not give orders. Only the squad part of the points will go toward your unlocks. So let's say you get a squad savior, you get 25 for the savior and 25 for the squad part, only 25 points will go in your perk progress.
You lose your progress toward your next level and a level when you wipe. If you are alone, you will wipe everytime you die.
From what I read, the upgrades are in individual, however, as I said before, they require squad play to unlock.
Best Answer
A bit of forum trawling later; looks like this is a known bug if a commander logs off when a EMP UAV is up.
http://battlelog.battlefield.com/bf4/en/forum/threadview/2955065217480972721/