is it always the same object that's not found?
objects named 'ShapeOrig' are usually nodes created by a deformer which the author of your script may not have antipated...but I imagine the whole point being deformers getting baked and exported
Sadly you'll probably need to fix the script, or post it here and hope someone has the time to help you out further
Also if this does what I think it does, which is export only the obj mesh at several points in time without the rig and all that stuff, it might be faster to write a more basic script that briefly does what you want.
//from frame
currentTime 1;
//to frame
$targetTime = 24;
//files prefixed with name
$name = "tmp";
$path = "scenes";
//enable save as obj
loadPlugin "objExport.mll";
for( $t = currentTime -q ; $t < $targetTime ; $t+=1 )
{
//shift time to current iteration
currentTime $t;
file -force -exportSelected -options "groups=1;ptgroups=1;materials=1;smoothing=1;normals=1" -typ "OBJexport" ($path+"/"+$name+"_"+$t+".obj");
}
This is simply far more brief and hence easier to fix, of course it lacks all the features of the other script.