errorlog fills after update to 17.06: 'Hook c2s_copy_session crashed when running mod_privacy:c2s_copy_session/2'

[github-tomster]

What version of ejabberd are you using?
1:17.06

What operating system (version) are you using?
Ubuntu Linux 16.04.1

How did you install ejabberd (source, package, distribution)?
jabber.at
updated via webmin

What did not work as expected? Are there error messages in the log? What
was the unexpected behavior? What was the expected result?
unfortunately an ejabberd update slipped tru when i last updated the machine.
since the update the log fills with errors, though ejabberd seems to work fine.
the error.log file starts with the line:

2017-07-16 13:34:51.501 [error] <0.1132.0>@gen_mod:validate_opts:514 unknown option 'registration_watchers' for module 'mod_register' will be likely ignored, available options are: subject, body

and then fills with these:

2017-07-16 13:36:23.796 [error] <0.1294.0>@ejabberd_hooks:safe_apply:383 Hook c2s_copy_session crashed when running mod_privacy:c2s_copy_session/2:

** Reason = {error,function_clause,[{mod_privacy,c2s_copy_session,[{file,"src/mod_privacy.erl"},{line,414}],[#{stream_restarted => true,mgmt_ack_timeout => 60000,lserver => <<"myjabber.domain">>,pres_timestamp => {1500,204917,266778},tls_verify => false,mgmt_timeout => 300,lang => <<"en">>,tls_options => [compression_none,{protocol_options,<<"no_sslv3">>},{certfile,<<"certfile">>}],stream_compressed => false,ip => {{theuserip},60538},stream_header_sent => true,mgmt_state => inactive,mgmt_resend => if_offline,server => <<"myjabber.domain">>,mgmt_stanzas_req => 0,csi_state => active,jid => {jid,<<"theusername">>,<<"myjabber.domain">>,<<"theuserressource">>,<<"theusername">>,<<"myjabber.domain">>,<<"theuserressource">>},mgmt_queue_type => ram,sockmod => ejabberd_socket,stream_authenticated => true,mod => ejabberd_c2s,conn => c2s_tls,stream_version => {1,0},csi_queue => {0,#{}},stream_id => <<"5760700331447186294">>,pres_last => {presence,<<>>,available,<<"en">>,{jid,<<"theusername">>,<<"myjabber.domain">>,<<"theuserressource">>,<<"theusername">>,<<"myjabber.domain">>,<<"theuserressource">>},{jid,<<"theusername">>,<<"myjabber.domain">>,<<>>,<<"theusername">>,<<"myjabber.domain">>,<<>>},undefined,[{text,<<>>,<<"on¡the¡line">>}],undefined,[{xmlel,<<"c">>,[{<<"xmlns">>,<<"http://jabber.org/protocol/caps">>},{<<"node">>,<<"http://conversations.im">>},{<<"hash">>,<<"sha-1">>},{<<"ver">>,<<"XtldZzOEZQxzSl2QYcF/lOUQZ1g=">>}],[]},{xmlel,<<"idle">>,[{<<"xmlns">>,<<"urn:xmpp:idle:1">>},{<<"since">>,<<"2017-07-16T10:40:16.060Z">>}],[]}],#{ip => {theuserip}}},stream_state => wait_for_bind,tls_required => true,mgmt_stanzas_out => 0,mgmt_stanzas_in => 0,pres_a => {0,nil},socket_monitor => #Ref<0.0.1.5630>,stream_direction => in,zlib => true,stream_encrypted => true,resource => <<"theuserressource">>,tls_enabled => true,xmlns => <<"jabber:client">>,owner => <0.1294.0>,socket => {socket_state,fast_tls,{tlssock,#Port<0.19325>,<<>>},<0.1293.0>},user => <<"theusername">>,access => c2s,auth_module => ejabberd_auth_mnesia,mgmt_max_timeout => 300,stream_timeout => {30000,-576455299293},mgmt_max_queue => 1000,...},...]},...]}

** Arguments = [#{stream_restarted => true,mgmt_ack_timeout => 60000,lserver => <<"myjabber.domain">>,pres_timestamp => {1500,204917,266778},tls_verify => false,mgmt_timeout => 300,lang => <<"en">>,tls_options => [compression_none,{protocol_options,<<"no_sslv3">>},{certfile,<<"certfile">>}],stream_compressed => false,ip => {{theuserip},60538},stream_header_sent => true,mgmt_state => inactive,mgmt_resend => if_offline,server => <<"myjabber.domain">>,mgmt_stanzas_req => 0,csi_state => active,jid => {jid,<<"theusername">>,<<"myjabber.domain">>,<<"theuserressource">>,<<"theusername">>,<<"myjabber.domain">>,<<"theuserressource">>},mgmt_queue_type => ram,sockmod => ejabberd_socket,stream_authenticated => true,mod => ejabberd_c2s,conn => c2s_tls,stream_version => {1,0},csi_queue => {0,#{}},stream_id => <<"5760700331447186294">>,pres_last => {presence,<<>>,available,<<"en">>,{jid,<<"theusername">>,<<"myjabber.domain">>,<<"theuserressource">>,<<"theusername">>,<<"myjabber.domain">>,<<"theuserressource">>},{jid,<<"theusername">>,<<"myjabber.domain">>,<<>>,<<"theusername">>,<<"myjabber.domain">>,<<>>},undefined,[{text,<<>>,<<"on¡the¡line">>}],undefined,[{xmlel,<<"c">>,[{<<"xmlns">>,<<"http://jabber.org/protocol/caps">>},{<<"node">>,<<"http://conversations.im">>},{<<"hash">>,<<"sha-1">>},{<<"ver">>,<<"XtldZzOEZQxzSl2QYcF/lOUQZ1g=">>}],[]},{xmlel,<<"idle">>,[{<<"xmlns">>,<<"urn:xmpp:idle:1">>},{<<"since">>,<<"2017-07-16T10:40:16.060Z">>}],[]}],#{ip => {theuserip}}},stream_state => wait_for_bind,tls_required => true,mgmt_stanzas_out => 0,mgmt_stanzas_in => 0,pres_a => {0,nil},socket_monitor => #Ref<0.0.1.5630>,stream_direction => in,zlib => true,stream_encrypted => true,resource => <<"theuserressource">>,tls_enabled => true,xmlns => <<"jabber:client">>,owner => <0.1294.0>,socket => {socket_state,fast_tls,{tlssock,#Port<0.19325>,<<>>},<0.1293.0>},user => <<"theusername">>,access => c2s,auth_module => ejabberd_auth_mnesia,mgmt_max_timeout => 300,stream_timeout => {30000,-576455299293},mgmt_max_queue => 1000,shaper => c2s_shaper,sid => {{1500,204895,7},<0.1294.0>}},#{stream_restarted => ...,...}]

is the log helpful in any way?
what should i change/correct?

[tmelikoff]

This has been fixed upstream with this commit.
See: processone/ejabberd#1842
Will be fixed in 17.08.