I'm receiving an error message that if I add one additional member to my board, it would 'exceed the workspace collaborator limit' however I am not at the limit just yet - we've got 8 out of 10 people on there, so in theory I should be able to add 2 additional members. I think this is a bug/glitch with the platform since the collaboration limits came in recently, because I can see other people are experiencing this issue also.