I OPENED MY AUTOCAD MEP THIS MORNING AND IN THE LOWER RIGHT CORNER OF THE SCREEN THERE WAS A BOX THAT CAME UP TELLING ME THAT MY CATALOG NEEDED TO BE UPDATED SO I CLICKED ON THAT AND RAN IT, NOT KNOWING THAT IT WAS GOING TO TAKE ALL DAY TO UPDATE, SO I STOPPED IT IN MID-STREAM (THINKING I COULD CONTINUE IT LATER) NOW IT WON'T LET ME OPEN UP THE AUTOCAD MEP. WHAT DO I NEED TO DO TO FIX THIS.
PLEASE HELP CAN'T WORK!!
Can you describe what happened when you cancelled the catalog regen, Did AMEP lockup / crash / exit back to Windows? Assuming AMEP is closed and not running, what error do you get when trying to restart AMEP?
If you haven't customized AMEP much, perhaps resetting AMEP back to factory settings is an option. Start > Autodesk > AutoCAD MEP xxxx > Reset Settings to Default
If all you were doing was running a catalog regen when you canceled the program then what is wrong is that your catalog is hosed. To regenerate it you are going to have to use the stand along program AecbCatalogEditor.exe found at C:\Program Files\Autodesk\AutoCAD 2014\MEP
Start that program up and then navigate to the catalog that did not regen correctly. Once that catalog is open use the Tools->regenerate catalog menu item on the toolbar. This should regenerate your catalogs outside of Autocad MEP. Once you catalog is regenerated Autocad should start.
This will only happen if you have one and only one catalog for a specific domain. Since it cannot find a catalog then Autocad MEP will not start.
This is my best guess at least.