This simple plugin tries to repair IQ packets which have no 'id' attribute. According to RFC 3920 (Page 51) an 'id' attribute is required for IQ stanzas. Openfire 3.6.0a and 3.6.1 have an bug associated with this fact, which causes client disconnects. This problem is discussed here.
If an packet has no 'id' attribute this plugin does modify the packet by simply adding an 12-digit random 'id'.
By default the plugin write a short log entry in 'info.log' each time it repairs a packet. You may disable logging by setting system property plugin.dropper.log to false. You will need to restart the plugin after changing this property.
The plugin is named 'Dropper' for historical reasons. First attempt to solve the problem was simply dropping these packets.