Alt+Eraser Pop up error "Could not use history eraser because..."

How I work is I use shortcut keys to rapidly flutter between paint tools and eraser.  I also use ALT a ton to sample colors from the image for painting.

While doing all this rapid movement I sometimes accidentally think i'm on the paint tool and I hit ALT to sample, but i'm on the erase, and a whole entire error (X) dialog pops up that I have to hit OK on highly disrupting my work.  

I attached an image of the error.

How can I get rid of this?  I would like anything else. May be it just makes a ding noise. May be nothing happens. Anything other than this OK button click showing up on my other monitor that I have to go over and click on or whatever.   

Also it would be cool if it just got the color anyways with alt that way when i realize i'm on the eraser tool I just switch to the paint tool with my shortcut and keep rollin' no problem.  That would be great.

Thanks.