I assume that Prime itself 'works', in the sense that you can start a new worksheet and enter expressions....
Do you have a diagonal banner across the worksheet and/or, if you type on the worksheet:
mean(1=
is the result?:
an error message, then you do not have an active (trial) license.
If you get this:
a numeric result, then you have an active (trial) license, and the converter, if installed(!), should work.
To get an active trial license, go to the main menu ( see below, arrow 1) and select options.
Then, on the license tab of the pop-up select "Get License" (arrow 2)

And follow the directions to get your trial license.
Success!
Luc

