This error message appears when attempting to open a Program that was created with later version of Dimension Pro. First make sure that you have updated Dimension Pro to 1.5 via the following instructions: http://www.cakewalk.com/Support/Knowledge-Base/2007013166/Dimension-Pro-Dimension-LE-1-5-Update If you already have installed the Dimension Pro 1.5 update, please verify that all of your Dimension Pro.dll files have been replaced with the later versions. Perform a file search for Dimension Pro.dll. View the properties of all of the Dimension Pro.dll files. Remove any Dimension Pro.dll that reads to be version 18.104.22.168. Make sure that all of your Dimension Pro version numbers read 22.214.171.124 or later.