Rockwell say:
Failed to save project in RSLogix 5000 753-80042029
493386 | Date Created: 06/05/2012 | Last Updated: 07/03/2015
RSLogix 5000 reports error 753-80042029 during attempting to "save" or "save as" ACD file
Answer
Go to File -> Save as
Change project name and project type to L5K
Hit Save
Close project
Open the L5K file and import project
Save ACD file
also....
Project name is invalid.
RSLogix 5000 software uses IEC-1131 Name Standard. It covers the following requirements:
minimum of six characters (Logix Designer application supports a minimum of 1 character)
starting with an underscore “_” or an alpha character (A-Z)
followed by one or more characters consisting of an underscore “_”, alpha character (A-Z) or a number (0-9)
spaces can not be used