I added a collaborator but I see a general faded avatar with a red x mark
Each collaborator you want to add under your account needs to have a FormTitan active account.
If he does not have an account, or if his account has not been activated, his card will be displayed in a disabled mode with a faded general collaborator avatar and red x mark.
Simply select his card and press on the envelope button above it to send him an invitation to FormTitan. Once he activates his account you will either see an approved collaborator avatar with a green v icon or the collaborator avatar image.