We've come across a bug recently that prevents a component's Extension Functions from re-enabling. I'm not sure if this is exclusive to 8.1.20, but it's the version we're currently using.
- Open the Component Scripting window and click on an Extension Function
- Enable said Extension Function
- Remove all lines from the script (this will leave Line 1 with the pre-defined function name/arguments and Line 2 with no text)
- Disable the Extension Function then click Apply or OK.
This will effectively lock us out of editing that script in the future. The only thing we can do is delete the component and create another (copying the component gives us the same issue). The Enabled checkbox looks to be selected when we click on it but the script text area doesn't enable. Clicking away from that extension function and back again will show that the Extension Function is still enabled.