It seems that 1.0-alpha4 only handles calls with one argument. The problem seems to be in following statement from XMLRPCServerRequest>>methodResponse: ret := ((srv key) perform: (srv value) with: (self params)). #perform:with: only expects one argument (per the comment) and fails if otherwise A solution is to use #perform:withArguments: like so: ret := ((srv key) perform: (srv value) withArguments: self params asArray). n.b. The parameters are stored in an OrderedCollection, which must be converted to an array Changeset attached: http://forum.world.st/file/n3328882/XMLRPCServerRequest-methodResponse.st XMLRPCServerRequest-methodResponse.st HTH, Sean -- View this message in context: http://forum.world.st/BUG-XMLRPC-1-0-alpha4-calls-with-1-arg-fail-tp3328882p... Sent from the Pharo Smalltalk mailing list archive at Nabble.com.