If I create an mtext entity with a diagonally stacked fraction and then click OK to complete creation the mtext editor takes several seconds to close. I have used mtext with stacked fractions for many years and have never had this problem. Now if I double click on an already created mtext entity that has a stacked fraction in it the same delay happens. If there are not fractions then the editor closes immediately.  If I do the above in a new drawing created from a template the same delay occurs. The text style used is the native AutoCAD standard style. I have searched far and wide for a solution. It has been recommended by others to replace dswhip.dll, but that did not solve the problem. I have AutoCAD installed on my laptop where this is not a problem, where the mtext editor closes immediately. I have cleaned the registry and done other clean-up to no avail. I hnow that if I reinstall AutoCAD the problem can be solved but I created have a lot of customization and do not want to create that again.
I would appreciate any tip or lead that might help with findinding a solution.
 
Thanks

Never do a reinstall of an AutoDesk product before first trying the REPAIR option.  The option can be found under the version of AutoCAD you are running in Windows Add/Remove Programs.What SHX or TTF font are you using in MText?