What's the plural form of misperformance? Here's the word you're looking for.
Answer
The noun misperformance can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be misperformance.
However, in more specific contexts, the plural form can also be misperformances e.g. in reference to various types of misperformances
or a collection of misperformances.