PUM Image 20 "Select Class" button produces error

Hello,

This is a question on how to reproduce the error described in Image 20 Bug 31844273

"With PUM18, after adding a class, there is a message to let students know that the class is

added to their Shopping Cart, BUT the "Select Class" button is still available at the bottom

of the page and it doesn't take the student back to the Shopping Cart.

If the student selects the "Select Class" button again, they will get an error

"Data being added conflicts with existing data. (18,2)".

Even when testing in a data base without Image 20 applied, I cannot replicate this error.

Has any been able to replicate it or verify that it is no longer happening?