Table of Contents Script

I’ve been using the popular table of contents generation script with omnigraffle version 5. Few months ago I updated to version 6.0.5 and now the script doesn’t run. I get the following error." OmniGraffle got an error: Can’t get every «class OGWS» of document 1."

Using OSX 10.9.5 (I’m not able to upgrade to Yosemite because of corporate restrictions).

Any solves or alternate ways of generating a TOC for the version of Omnigraffle I have?