When members are not able to book classes on Course Hub and the following prompt shows up:
This is because the current price line for the default membership associated with this payment plan is not included.
Let's take Lanie-Grace Massey as an example.
Choosing the Xperience One Concession as a Payment generates the error prompt above.
You would need to check the Payment Plan that is used via Course Pro.
Settings > Members > Payment Plans > Xperience 1 (Edit)
Need to make sure you are selecting XP1 CONCESSION, it should be a little bit gray if selected.
On the Edit Payment Option > HomePortal, click Edit
Take note of the Default Membership Number, which is the Default Price Line.
Scroll down until you see Memberships > Edit
It needs to be on the Selected Memberships. It was not there originally, so I had to add it to sort the issue for Active4Today.