This exception error message is thrown because the program event has been marked as members only when the client's Altru database is not using responsive layouts. Members only events can only be displayed online when the client is using a responsive layout. To resolve this issue you would need to switch to a responsive layout or remove the membership restriction from the event

Remove the restriction:
  1. Click tickets > program search >search for and select the program
  2. Click on the event list tab
  3. Click on the program event
  4. Click edit event
  5. Click on the gray square next to the membership restriction and press the delete button on your keyboard
Change to a responsive layout:
  1. Click web > page designer
  2. Choose a layout that has responsive in the title
  3. Click next > click next > click submit to finalize the form

When switching your web forms from a non responsive layout to a responsive layout you should consult with your web designer. Making this change could adjust the format of your web forms if you currently have custom CSS in your database. This task should be handled by someone who is familiar with HTML and CSS.