Its not aplugin by the way. And if you have used maya for a few years then you ahve used mel for a few years (you can NOT use maya and NOT use mel is impossible atleast for the foreseebale few years into future)
The problem is i dont have mac so i cant test whatever fix i would go and make, but it can be fixed by inserting a appropriate layout to the thing.
Ina ny case you dont actially nee dthe gui for anything just copy teh contents of proc treads to your script editor change the lines:
string $curve = textField -q -tx curveName;
to
string $curve = "yourCurveObjectName";
string $radioScale = radioCollection -q -select radioScaleCollect;
To
string $radioScale = "ZDepth"; // or YDepth or XDepth
string $duplicateType = radioCollection -q -select radioDupCollec;
To
string $duplicateType = "CopyTreads"; // or InstTreads
string $tread = textField -q -tx treadName;
To
string $tread = "nameOfYourTreadGeometry";