Hello,
After later investigation it seems this issue was target OS related, not if the prerequisite is installed or not. This means that if you have a prerequisite with 64-bit supported windows version option disabled, it won't be shown in the dialog when installing on such a machine. This can lead to the list in the dialog to be empty.
The only solution in this case is to use "Show only if..." using
VersionNT64 property as described in the following article:
How do I install resources based on the Operating System version?
We'll improve the behavior in this area by creating a property which will ease the dialog's conditioning, but the "Show only if" step will still be required.
All the best,
Mihai