Description
None of the fields you've selected for the Attributes of Interest parameter can be used for analysis. Once all of the invalid attributes were removed, none were left.
Solution
Select Attributes of Interest that have at least some variation in values. When all the values are the same, it is impossible to say that one is more similar than another. Also, the fields you select must exist with the same name and same data type in both the Input Features To Match layer and the Candidate Features layer. If the Attributes of Interest you select do exist in the Candidate Features but have a different data type or different name, you can use Add Field and Calculate Field to create new fields that match those in the Input Features To Match layer.