Replace is not supported with some types of datasource (Excel or text for example). If you extract your source it should work fine.
sure enough- I extracted and now it's there!
You would think the error message would be more helpful.....
true, it would be nice if error messages could distinguish between functions that are Not Available: Replace() and those that Don't Exist: FixThis()
greying out unavailable functions out on the select menu instead of hiding them might help the novice user..