I've been using mach 3 for a few years with no problem. Yesterday it stopped performing with any file that I opened...gave me a "bad character used " notice. Now when a file was loaded the directional keys didn't do anything. ..but without a file being opened the keys moved thru the movements like they are supposed to. I tried different files and even made a quick file...won't do anything when a file is opened...I make dxf with draftsight...convert with sheetcam...and use mach 3.   I'm not a computer guy so if you have any suggestions please keep it simple for me to understand...thanks
 

Try downloading the latest available version of Mach3  https://www.machsupport.com/downloads-updates/main-programs/ and installing it over the top of your existing version. (Please make a back-up copy of your existing Mach3 folder first, just in case any settings are overwritten).

Tweakie.

thanks...will try later today

I gave a try yesterday...I think that my cnc computer is shot...so now I have to buy a new computer. And the problem of hooking it up with...the driver, draftsight, sheetcam, mach3, etc,etc,etc.  I am terrified of this because I'm not too "computer knowledgeable"....always open to suggestions...or hands on assistance if any one is near west valley ny. Thanks

Just a tip but IMO it is better to use a dedicated PC just for running Mach and have all your CAD/CAM, etc. on another computer.

Tweakie.