Moderator’s note: Split from this thread.
I’m having the same problem. The mailing list block doesn’t appear in the communicate tab.
I’m running verxion 1.67. Error reporting is turned on, and I’m a super-admin. I can add people to the mailing list. I can send email to individuals and groups.
Also, when I give access to the mailing list module to other groups, it doesn’t appear for them in the control panel (other modules do).