I want to allow all stanzas from mutually subscribed users, so I have the following rule in both ::preroute and ::deliver chains: SUBSCRIBED? PASS. When a subscription request comes in from a remote domain, this leads to a stacktrace: May 12 06:49:57 s2sin55eb62fc4dd0 debug Received[s2sin]: <presence from='remoteuser@remotedomain.com' to='localuser@yax.im' xml:lang='en' type='subscribe'> May 12 06:49:57 rostermanager debug load_roster: asked for: localuser@yax.im May 12 06:49:57 rostermanager debug load_roster: loading for offline user: localuser@yax.im May 12 06:49:57 rostermanager debug load_roster: cache hit May 12 06:49:57 mod_firewall::deliver debug Chain "user/pass_acceptable" accepted stanza (ret false) May 12 06:49:57 rostermanager debug load_roster: asked for: localuser@yax.im May 12 06:49:57 rostermanager debug load_roster: loading for offline user: localuser@yax.im May 12 06:49:57 rostermanager debug load_roster: cache hit May 12 06:49:57 mod_firewall::deliver debug Chain "user/pass_acceptable" accepted stanza (ret false) May 12 06:49:57 yax.im:presence debug inbound presence subscribe from remoteuser@remotedomain.com for localuser@yax.im May 12 06:49:57 rostermanager debug load_roster: asked for: localuser@yax.im May 12 06:49:57 rostermanager debug load_roster: loading for offline user: localuser@yax.im May 12 06:49:57 rostermanager debug load_roster: cache hit May 12 06:49:57 rostermanager debug load_roster: asked for: remoteuser@remotedomain.com May 12 06:49:57 rostermanager debug load_roster: loading for offline user: remoteuser@remotedomain.com May 12 06:49:57 storagemanager error Failed to load storage driver plugin internal on remotedomain.com: unknown-host May 12 06:49:57 storagemanager warn Falling back to null driver for roster storage on remotedomain.com May 12 06:49:57 runnerAVGthxhc debug changed state from ready to error (ready) May 12 06:49:57 s2sin55eb62fc4dd0 error Traceback[s2s]: /usr/share/lua/5.2/prosody/core/storagemanager.lua:233: attempt to index field '?' (a nil value) stack traceback: /usr/share/lua/5.2/prosody/core/storagemanager.lua:233: in function 'open' /usr/share/lua/5.2/prosody/core/rostermanager.lua:132: in function 'load_roster' /usr/share/lua/5.2/prosody/core/rostermanager.lua:269: in function 'is_contact_subscribed' mod_firewall::user/pass_acceptable:63: in function '?' /usr/share/lua/5.2/prosody/util/events.lua:79: in function </usr/share/lua/5.2/prosody/util/events.lua:75> (...tail calls...) ...ules-enabled/mod_log_slow_events/mod_log_slow_events.lua:12: in function <...ules-enabled/mod_log_slow_events/mod_log_slow_events.lua:10> (...tail calls...) mod_firewall::preroute:19: in function '?' /usr/share/lua/5.2/prosody/util/events.lua:79: in function </usr/share/lua/5.2/prosody/util/events.lua:75> (...tail calls...) ...ules-enabled/mod_log_slow_events/mod_log_slow_events.lua:12: in function <...ules-enabled/mod_log_slow_events/mod_log_slow_events.lua:10> (...tail calls...) /usr/share/lua/5.2/prosody/core/stanza_router.lua:184: in function 'core_post_stanza' /usr/lib/prosody/modules/mod_presence.lua:240: in function </usr/lib/prosody/modules/mod_presence.lua:223> (...tail calls...) /usr/share/lua/5.2/prosody/util/events.lua:79: in function </usr/share/lua/5.2/prosody/util/events.lua:75> (...tail calls...) ...ules-enabled/mod_log_slow_events/mod_log_slow_events.lua:12: in function <...ules-enabled/mod_log_slow_events/mod_log_slow_events.lua:10> (...tail calls...) /usr/share/lua/5.2/prosody/core/stanza_router.lua:188: in function 'core_post_stanza' /usr/share/lua/5.2/prosody/core/stanza_router.lua:128: in function 'core_process_stanza' /usr/lib/prosody/modules/mod_s2s/mod_s2s.lua:573: in function 'func' /usr/share/lua/5.2/prosody/util/async.lua:127: in function </usr/share/lua/5.2/prosody/util/async.lua:125> I'm not sure whether this is triggered on the incoming request or on some auto-generated response or in the middle of them.

Isn't this a dupe of #1331 ?

Maybe, but nothing has happened for a year there and I forgot.