In that buy/try window, isn't there an option to indicate that you have a serial number? If you click that option and choose next I thought that would take you to the screen where you can enter your serial number.
I would have thought so, too. BUT, the window that opens has the "I have
serial number" button already selected, and there is no "next" button.
It's essentially a dead window with no way to continue.
You're probably going to have to contact Adobe customer support.
I'm sure you're right, alas.
Just FYI, apparently, running LR 5 exe works as we would have expected, and
the link to update to 5.5 comes right up when the program is opened. Takes
some time, of course (and wants to create a new catalog as well), but it