1) Create a model having an ODataAction.
2) Add a complex type KeyValuePair<string, object> to the model like this,
model.ComplexType<KeyValuePair<string, object>>();
3) Try accessing that action. ODataFormatter fails with model state error,
```
{Microsoft.Data.OData.ODataException: A top-level property with name 'IsUser' was found in the payload; however, property and collection payloads must always have a top-level property with name 'value'.
```
This is because ODataActionParameters is IDictionary<string, object> which is IEnumerable<KeyValuePair<string, object>>. So ODataFormatter thinks that ODataActionParameters is a EDM collection type.
2) Add a complex type KeyValuePair<string, object> to the model like this,
model.ComplexType<KeyValuePair<string, object>>();
3) Try accessing that action. ODataFormatter fails with model state error,
```
{Microsoft.Data.OData.ODataException: A top-level property with name 'IsUser' was found in the payload; however, property and collection payloads must always have a top-level property with name 'value'.
```
This is because ODataActionParameters is IDictionary<string, object> which is IEnumerable<KeyValuePair<string, object>>. So ODataFormatter thinks that ODataActionParameters is a EDM collection type.