on line 475, inside the getBlockvariables() method is missing a very important few chars that specify *which* block's vars to list. the existing code returns an array of block names:

** old code **
foreach(foreach ($this->blockvariables as $variable => $v){
** /old code **

should be:

** new code **
foreach(foreach ($this->blockvariables[$block] as $variable => $v){
** /new code **