This is definitely caused by receiving an invalid stanza from the component. An error is logged, but the component does not receive any error stanza. Then it breaks stanza routing in surprising ways: stanzas to the component are still routed, but stanza *from* the component are silently dropped. Restarting the component fixes the routing issue. jcp55cdaf949810 warn Rejecting stanza with no 'to' address connjjNF9c7tHDJE error Error calling onincoming: /usr/share/lua/5.1/prosody/util/stanza.lua:469: bad argument to error_reply: got stanza of type error which must not be replied to stack traceback: [C]: in function 'parse' /usr/share/lua/5.1/prosody/util/xmppstream.lua:290: in function 'feed' /usr/lib/prosody/modules/mod_component.lua:319: in function 'data' /usr/lib/prosody/modules/mod_component.lua:331: in function </usr/lib/prosody/modules/mod_component.lua:329> [C]: in function 'xpcall' /usr/share/lua/5.1/prosody/net/server_epoll.lua:240: in function </usr/share/lua/5.1/prosody/net/server_epoll.lua:226> (tail call): ? /usr/share/lua/5.1/prosody/net/server_epoll.lua:456: in function 'onreadable' /usr/share/lua/5.1/prosody/net/server_epoll.lua:1044: in function </usr/share/lua/5.1/prosody/net/server_epoll.lua:1036> [C]: in function 'xpcall' /usr/bin/prosody:78: in function 'loop' /usr/bin/prosody:83: in main chunk [C]: ?

Hmmm after all the error stanza is received by the component, my bad. But then the component is in this weird "receive-only" state.