I've managed to upgrade a 5.5 installscript version to 2012 to the point where it compiles. When I attempt to build, I get an error (-7261) indicating that my target platform is invalid. No amount of changing the options in the target platform does anything. The old 5.5 install did have targets to platforms no longer supported (i.e. NT). Is this hidden somewhere that is being picked up by the new build? I've grepped through everything but don't see and secret hiding places for target platform info.
Since this is such an old version you're updating from, you might be able to solve the problem by first upgrading to an intermediate version. For example, if you have InstallShield 11 you could go from 5.5 to 11, then try going to IS2012. I don't think you'd need a licensed copy of the older version, a demo would do. But I'm not sure if Flexera still has older versions available for download.
