Today i couldnt install the mailing module. When i was installing it, the communicate tab was not modified to display the “send to mailing list” box.
After two hours of investigation, i found that it was during the install of EE, i changed the db tables prefix from exp_ to something else.
After modifying all the sites and custom modules to use the default prefix, i have reinstalled the mailing list module and now it work properly.
So just a head up, some modules like this one doesn’t manage a prefix different than the default EE one apparently.