We are running 1.5.1 on a new Beach Farm playing with 3 players on local co-op. When any Player opens either of the first two Journal entries (and probably all of the rest), the game crashes. Is there anything I can do to help you fix this issue?
What language are you playing in? Are you on Windows, Mac or Linux?
If you follow the instructions here: http://smapi.io/log for your platform, is there a file in that ErrorLogs folder for the players who crashed? If so, could you upload it here?