The extension could not be loaded because it was not properly signed

Hey,

I've been using a script for photoshop which was created by one of my colleagues, he left the company. I need to edit the scrip a little bit, but whenever i save the JSX file and try to open the extension within photoshop I get the error message that is in the title. I tried it with not modifying anything in the scrip just resaving it, and the error message pops up. If i replace the file with the old JSX which was made by my colleague, then it works again. Seems like the error message is tide to any edition to any files. He made the script in extendscrip tool kit, I'm using the same software for editing and the issue persists. Within the scrip folder there's a folder name META-INF containing signatures.xml, could it be that there's some sort of protection from editing built in within the script? Anyone had the same problem or any ideas how to solve it, please don't hesitate! Thanks a lot!