I am new to the game, joined with my husband and 2 teenagers. We all joined at the same time, same ship, same block. We all meet up in game, one tryed to invite the others to party, 2 were "blacklisted unable to send" 1 was "you can't invite that player" but the last can invite everyone BUT only 1 can join. Can anyone help fix this ?

@katana210 after crazy digging I found the answer

On xbox, if your friend is "muted or blocked" the game will automatically blacklist that person. Tested workes. I really hope this helps others, I know not being able to play with friends will brake a game that could potentially be awesome!

It was an issue in Closed Beta as well.

There was another thread recently created that I replied to for this issue before you made this thread: https://forum.pso2.com/topic/930/blacklist-nonexistant-on-xbox-version

PC users won't have this problem.