Put this in after the datablock.
echo("SkeleBody Check:" SPC isFile(DatablockName.shapeFile));
Will echo 1 if the file exists, 0 if the file does not exist. If it does not exist, I suggest using a more explicit filepath.
(Add-Ons/Player_Skeleton/shapes/SkeleBody.dts)
If it does exist, then the dts is invalid.