Suddenly can't use WASD controls

[Suddenly can't use WASD controls]

Upon seeing your comment, I verified the game files on Steam and loaded up Drawdown 2035, and the controls are working again.  Thank you so very much for helping me with this issue; you are a godsend.

[Suddenly can't use WASD controls]

I started the journey of getting into Arma 3 the other day, and last night I completed the prologue of the campaign.  No problems at this point.  This morning, less than twelve hours after the last session and seemingly without any rhyme or reason, I suddenly could not use the WASD controls, or other letter key controls, to move or accomplish anything.  The arrow keys work, but I hate using them due to how unnatural they feel.  I found this issue at the very beginning of the Drawdown 2035 mission.  I checked the key bindings and found they were setup for WASD configuration.  I eventually learned that the regular letter keyboard controls work if I hold the Alt key; however, it keeps my character moving in a single direction in a way that's difficult to stop.  At this point, the game is unplayable until I can get this problem solved, and I want to play it.  If anyone has any idea what my problem is and is willing to help me, I would be grateful if you could reply to this post.