An operation has many parameters (you can configure what counts as \u201cmany\u201d parameters for your model\u201d).
Consequences
Operations with many parameters are harder to maintain and extend. It typically indicates that an operation has many options that can be on it. Every time another option is discovered and the class needs to be changed you will need to add either another parameter and change all calls to the operation, or add an overload. If too many overloads are added the code will become messy and hard to use.
Strategy
If you are happy with the operation having a high number of parameters (it is not always incorrect) then ignore this error.
Consider whether:
A data structure or class can be used to hold coherent sets of parameters together. If you can see other operations that would also use this structure then this is usually a good idea.