Publishflow Block : Requirements
From MoodleDocs
The Publishflow block makes an important use of MNET RPC calls at block level.
Running the Publishflow architecture needs to add an identified patch called : extending RPC handling to blocks in Moodle 1.9. This handling is implemented in Moodle 2.0.
Tracker reference is : http://tracker.moodle.org/browse/MDL-23194