I am using IS2013 Premier. In a Basic MSI project we have the option of assigning separate GUIDs for each Release (Releases, General, Product Code). This is very useful, for example, if you have 2 releases you can easily detect if the opposite release is already installed. Unfortunately we don't seem to have that same capability for a Suite project. So if I have multiple Suite Releases I can't tell if the other release is already installed. I have played around with events and I am able successfully to set a property based on whether or not MSI packages are installed. However, I can't make the detection of that property work as an Exit condition on the General Information tab... presumably because the Exit conditions are evaluated prior to my property being set by the 'On Begin' event.
I got it done by setting up a property with events. The not-so-obvious part about this is that apparently the Exit Conditions on the General Information tab do not get evaluated in Maintenance mode. Since Suite releases all have the same GUID, installing another release means Maintenance mode. So the trick is to insert another Wizard page prior to MaintenanceWelcome with a Visible condition using the property I set with Events.
