Better error message instead of "array is not unique"

[MaxMatti]

Took me about 30 minutes to figure out that the error message that is being generated here refers to the fact that my required field contained an item twice. Also it's only mentioned in a subError and the error itself is being presented as "No valid results for anyOf". Please modify this error message to be more concise, thank you.

[vearutop]

Hi, could you share the error message you got and what you would prefer to see?