Will RSView ME 4.0 with with v5.0 activation?

I have Factory Talk View v5.0 and a temporary 30 day activation installed while I'm waiting for the official package to arrive. I've now discovered that the customer is using v4.0 (RSView ME). I have the install files for v4.0. If I uninstall v5.0 and install v4.0 is the activation likely to continue to work? Can I have both versions installed at the same time? I don't want to accidentally mess up the activation since I'm heading to the job site in just a few days.

I know I can save a v4.0 runtime with v5.0 but I'd prefer not to upgrade their application to something they can't use.

You'll need a legacy license for 4.0, the new Factory Talk administration activation system does not play nicely with 4.0.

I believe it is a .net framework issue, but can't remember the details, just know that for work I need both a Factory Talk activation for my 5.0 install, and legacy activations for my 4.0 install on a virtual machine.

Maybe I'm not understanding?

Perhaps I am not understanding, but you did say that you are aware that you can download the file as a 4.0 runtime file. Working from memory, but just a question, can you not archive the file as a 4.0 also?