Attached is a ZIP file containing a repro installer AIP (for version 1.0 and 2.0 of a test install) for the following problem I've observed in Advanced Installer:
1. Create a new installer
2. Set to "Allow side by side installs of different product versions"
3. Added multiple instances
4. Install 2 instances of version 1.0
5. Create Major Upgrade to version 2.0
6. Run 2.0 installer and select instance #0 - update works
7. Run 2.0 installer and select instance #1 - installer goes to the "Resume" dialogs and if you continue it fails, looking for the prior version's MSI
What I've described is basic functionality for multiple instances. My expectation is that I can have instances of version 1.0, version 2.0 and version 3.0 all side by side. Is that incorrect? If so, multiple instances is largely useless for me.
I will also send a larger ZIP file with the actual .exe installers and some additional logs.