We need files from this folder for solve your problem. C:\Users\<Name>\AppData\Local\Arma 3\
Can you upload somewhere in winrar package please?
When package will be smaller than 2,097k, so you can attach here. When package will be bigger, please use some free sharing service and post link here. Thank you.

http://feedback.arma3.com/how-to-user.html.html

http://www.sendspace.com/file/wc06tl Here it is. Thank you for quick reaction!

Well, it loaded today and I played multi-player for few hours, but then it again ceased to work. Maybe some driver issues? Not resolved, looking forward for today patch.

What is the situation after the patch?

I should specify that I was able to briefly play after patch from 15th (462 MB). I am at the work now, so I will download DEV patch asap when I am home (but I do not see anything on Beta Development branch thread for 16th yet). Will let you know immediately, again thanks for caring!

I guess you can mark this as resolved - after download of patch game started, then it again ceased to do anything. I restarted Steam and then it worked, but it seems that I always have to restart Steam if I want to click Play after once closing game. A bit annoying, but still better than not working at all!

Mass closing ancient tickets with no activity this year; assume fixed or too trivial etc.

If this issue is still relevant in current dev build, please create a new ticket referencing this one and request for it to be re-opened.