What steps will reproduce the problem? 1. Create a new MUC 2. Try to send a PM 3. No message is forwarded by the server, no error to the user What version of the product are you using? Prosody 13 The Problem is fixed once you change the PM config option, so it seems the value on the server is initialized with NULL but shows something different in the config form. Traceback: Mar 04 23:29:25 c2s557fd47a8260 error Traceback[c2s]: /usr/lib/prosody/modules/muc/restrict_pm.lib.lua:98: attempt to compare nil with number stack traceback: /usr/lib/prosody/modules/muc/restrict_pm.lib.lua:98: in field '?' /usr/lib/prosody/util/events.lua:81: in function </usr/lib/prosody/util/events.lua:77> (...tail calls...) /usr/lib/prosody/modules/muc/muc.lib.lua:911: in function </usr/lib/prosody/modules/muc/muc.lib.lua:884> (...tail calls...) /usr/lib/prosody/util/events.lua:81: in function </usr/lib/prosody/util/events.lua:77> (...tail calls...) /usr/lib/prosody/core/stanza_router.lua:188: in upvalue 'core_post_stanza' /usr/lib/prosody/core/stanza_router.lua:128: in upvalue 'core_process_stanza' /usr/lib/prosody/modules/mod_c2s.lua:361: in upvalue 'func' /usr/lib/prosody/util/async.lua:149: in function </usr/lib/prosody/util/async.lua:147>