When you right click, under "Editor Settings" check "Show Toolbar."
Select all the text.
In the "Width Factor" toolbox change the value BUT DON'T HIT ENTER TO SET IT.
Hit "OK" on the Toolbar and AutoCAD will crash. And of course, like anytime my AutoCAD crashes, while waiting for it to check the error it doesn't find a solution.
I don't know if it's important, but I'm running AutoCAD with the ribbon instead of with the "classic" toolbars. I had the "Show Toolbar" option selected inside the MTEXT editor because I have not found a way to change the width factor in the "Multiline Text" tab that comes us when you are using the ribbon.
If there is a resolution for this please let me know. Otherwise I would hope to see this fixed in SP1. Thank you.