Trying to start ejabberd I got errors such as these:
2017-09-01 00:35:06.928 [error] <0.37.0> CRASH REPORT Process <0.37.0> with 0 neighbours exited with reason: {aborted,{“Cannot read schema”,”/var/lib/ejabberd/schema.DAT”,{error,{file_error,”/var/lib/ejabberd/schema.DAT”,eacces}}}} in application_master:init/4 line 133