Cleared that one by monkeypatching the set_channel_property method:

def set_channel_property(channel, property, argument=nil)
  channel = normalized_channel_name(channel)
  mode channel, "+#{property}", argument
end

Got past this by removing the Authenticator leaf. leaves.yml had that configured with a "type: op".

Now getting this problem:
Example (Stem): << :renier!~renier@blah.blah.blah PRIVMSG #LRTM :!points renier +1
Adapter not set: default. Did you forget to setup?
/usr/lib/ruby/gems/1.8/gems/dm-core-0.9.11/lib/dm-core/repository.rb:28:in adapter' /usr/lib/ruby/gems/1.8/gems/dm-core-0.9.11/lib/dm-core/repository.rb:61:inread_many' /usr/lib/ruby/gems/1.8/gems/dm-core-0.9.11/lib/dm-core/model.rb:257:in all' (eval):34:infind_person' (eval):51:in parse_change' (eval):31:inpoints_command' ./libs/leaf.rb:641:in send' ./libs/leaf.rb:641:incommand_exec' ./libs/leaf.rb:627:in command_parse' ./libs/leaf.rb:225:inirc_privmsg_event' ./libs/leaf.rb:322:in database' ./libs/leaf.rb:223:inirc_privmsg_event' /usr/lib/ruby/gems/1.8/gems/facets-2.7.0/lib/core/facets/kernel/respond.rb:18:in send' /usr/lib/ruby/gems/1.8/gems/facets-2.7.0/lib/core/facets/kernel/respond.rb:18:inrespond' ./libs/stem.rb:475:in broadcast' ./libs/stem.rb:473:ininitialize' ./libs/stem.rb:473:in new' ./libs/stem.rb:473:inbroadcast' ./libs/stem.rb:472:in each' ./libs/stem.rb:472:inbroadcast' ./libs/stem.rb:529:in start' ./libs/stem.rb:529:ineach' ./libs/stem.rb:529:in start' ./libs/foliater.rb:226:instart_stems' ./libs/foliater.rb:221:in initialize' ./libs/foliater.rb:221:innew' ./libs/foliater.rb:221:in start_stems' ./libs/speciator.rb:106:ineach_stem' ./libs/speciator.rb:106:in each' ./libs/speciator.rb:106:ineach_stem' ./libs/foliater.rb:220:in start_stems' ./libs/foliater.rb:39:inload' ./libs/genesis.rb:173:in invoke_foliater' ./libs/genesis.rb:45:inboot!' script/server:12
Example (Stem): >> PRIVMSG #lrtm :Listener Scorekeeper::Controller raised an exception responding to irc_privmsg_event: Adapter not set: default. Did you forget to setup?

But I configured the database (using sqlite3) in database.yml...