I was playing bootcamp I noticed I can't stop running sometimes and I die.
Usually when I lag I stop but here I keep running and I can't control my mouse.
I'm not sure how to fix this, when I come on it still happens.

You could possibly just be in chat lock where you have never actually left the input section of chat.
This can also be caused by heavy client-side lag. Try activating optimisation settings as this will reduce the lag and hopefully help prevent this from happening.

I'll try and its not chat lock and I dont usually lag bad like other mice keep running even though they arent but i will try op mode and see if this helps.

EDIT": I already seem to have it on. Its not chat lock or the lag its a bug within the game caused by even the tiniest amount of lag apparently.

This happens to me too, sometimes.I just press left, if I run in left, right, if I run in right.Tell me if this works for you too.

I think I had this problem on several other games awhile ago, are you using Internet Explorer?

This happens to me too, sometimes

(Might be inacurrate...)
Why don't you try using the standalone? That could be one of your solutions to the glitch. I have this problem sometimes, but it's a whole different story, on my side. I move my mouse but then my keyboard decides to be a butt and make me move a different way, like if I press the right arrow, then it turns left. I think it's because the keyboard reversed the keys.
Solution 2;
Have you tried refreshing? That might be another solution to your problem.
Solution 3;
Try new browsers, sometimes browsers tend to lag. I have this problem a whole lot, so I switch to my other browser. The game works fine for me if I switch browsers.
(Sorry if my posts are incorrect, dun hurt me! T.T)