Reading mouse screen position causes crash

So when I try to do this in a LocalScript:

local mx, my = mouse.X, mouse.Y

the client crashes. This was not the case before the latest Studio update.

EDIT: This is also the case with mouse.ViewSizeX and mouse.ViewSizeY. This is a massive problem to me because I was using these in a project I’m working on.

Oh wow, roblox dun goofed…

I will check my places that uses mouse.X,mouse.Y when I get home.

The hyperlaser causes me to crash.

We found the cause. It was a very minor change to fix it. We should have a patch later tonight to fix this behavior.

In the mean time, if you need to develop and test a place that uses mouse.X and mouse.ViewSizeX consider saving a local file of your place and editing it using an older version of Roblox from

Apologies that the work-around sucks. Let me know if you need more help with the temporary work-around.