I can't achieved to do a major upgrade on a multi-instance setup.
For example, 2 instances are installed on the same computer. - I've created a major upgrade (version, product, package code) but I have strange errors: The first installed instance is not seen and the major upgrade does not work either way (mixing between instances). - I tried to give each instance a dedicated upgrade code and to change their product code individually but it does not work: Instance list is not shown and only first one is updated. Further install now only show the first instance upgraded... (So all other installs can not be upgraded)
How can I achieve this? I would like to install n instances and then launch a major upgrade, choose the instance to upgrade and upgrade it... that's all.
