Issue Summary

On a Trello Template board, the "Add member" option is not available on cards by default. However, when an admin drags and drops a member from the top-right of the board onto a card, the member is successfully added. Once a member is added this way, a "" button appears on the card to add additional members - but clicking the "" button does not work. Both methods should behave consistently.

Steps to Reproduce

1. Open a Trello Template board

1. Open any new card on the Template board (one with no pre-existing members)

1. The " Add member" option is not available in the card back as per the limitation.
2. Now try dragging a member from the top-right of the board and dropping them onto the card.
3. Notice that the member gets added to the card back.

1. Click the "+" button next to Members to attempt to add a member

1. Observe that clicking "+" has no effect

Expected Results

Both the "+" button and the drag-and-drop method should work consistently for adding members to cards on a Template board, or neither should be available.

Actual Results

The "+" button to add members does not respond/work on Template board cards. However, dragging and dropping a member from the top-right of the board onto the card works successfully. This inconsistency is confusing for users.

Workaround

Users can work around this by dragging and dropping members from the member list in the top-right of the board onto the card, instead of using the "+" button. However, members will not be copied to the new board created from the template.