Context: You have LabVIEW 8.5 and 2009 installed on your Win XP Pro machine. You have a project you'd like to be able to open in either version, so you copy the version created in 8.5 to a new location. You open the new version in 2009, and save all the files in the new version.
Problem: LabVIEW 8.5 will no longer open. It will get to the Getting Started screen, stay there for a few seconds (none of the links will work), and then disappear completely with no explanation. Or, you might be able to get to a bona fide Getting Started screen with working links, but the instant you try to open the project with 8.5, it disappears.
Possible Cause: You inadvertently overwrote some common files not in your normal hierarchy; perhaps you have some user.lib files that you've written in order to have access to them in any project. LabVIEW 2009 could have overwritten those files and saved them in the 2009 version.
Solution to Possible Cause: Open the project in LabVIEW 2009, and carefully investigate your VI hierarchies and File View in the Project Explorer to determine what files you might have overwritten. You will need to save those files for previous version, and make sure all links are updated (i.e., that all files know where dependent files are).
