My most popular script for Adobe Illustrator is “Find and Replace Graphics”. This script is useful if you have generic path objects that you need to switch to another shape, or replace with a proper symbol. Most of the time this script works but occasionally it errors out saying a group cannot be moved, the end.
If you are getting this error, you can either (a) unlock the top-most layer in your document and try again, or (b) copy and paste the subject objects into a new document, run the script there, and then copy-paste them back to your original document.
The bug is related to the fact the script is rather dumb about layer detection. In fact, you’ll notice it moves all your objects off their original layer and onto the bottom-most layer in the document.
A forthcoming update will fix this underlying object-layer problem, and the locked-layer bug.