Unknown error after updating!

[ornate plinth]

No clue what this is... like at all. this piece of code has always worked and now it doesn't. any help, please!

[burnt shoal]

Updating?
You are trying to redefine a function that already exists in one of of the parent scripts/types you are extending from

Parent signature in the error message is cut off in the end, but looks like the original function has a different return type