Subject: Query Regarding RulesEngine: Execution error - "Unable to cast object of type 'System.Linq.Expressions.InstanceMethodCallExpression1' t.o type 'System.Linq.Expressions.ParameterExpression"

Hello,

I am writing to seek assistance regarding an issue we are encountering while using the RulesEngine. We have a RulesExpression with multiple rules, where the output of one rule is used as input for another rule. However, we are experiencing an error during the execution of the second rule's expression.

Here are the details of our RulesExpression:

{
  "RuleExpression": [
    {
      "WorkflowName": "DataBuilder",
      "Rules": [
        {
          "RuleName": "GetAuthorDetails",
          "Expression": "input1.ApiOutputs.FirstOrDefault(x => x.ExternalApiIdentifier == \"NessieSearchPeopleApi\") != null",
          "Actions": {
            "OnSuccess": {
              "Name": "OutputExpression",
              "Context": {
                "Expression": "input1.ApiOutputs.FirstOrDefault(x => x.ExternalApiIdentifier == \"NessieSearchPeopleApi\").Input.people"
              }
            }
          }
        }
      ]
    },
    {
      "WorkflowName": "DataBuilder",
      "Rules": [
        {
          "RuleName": "GetAuthorDetails",
          "Expression": "input2 != null",
          "Actions": {
            "OnSuccess": {
              "Name": "OutputExpression",
              "Context": {
                "Expression": "input2.FirstOrDefault(x => x.fullName != null);"
              }
            }
          }
        }
      ]
    }
  ]
}

We have a C# code snippet that parses and executes the rules:

var newInput = new Object();
var workflows = JsonConvert.DeserializeObject<List<Workflow>>(payload.RuleExpression.ToString());
foreach (var workflow in workflows)
{
    var workflowList = new List<Workflow>();
    workflowList.Add(workflow);
    var bre = new RulesEngine.RulesEngine(workflowList.ToArray(), null);
    List<RuleResultTree> resultList = bre.ExecuteAllRulesAsync("DataBuilder", resolverInput, newInput).Result;
    var resultFromRule = resultList[0].ActionResult.Output;
    newInput = resultFromRule;       
}

During the execution of the second rule's expression, we are encountering the following error: 'Exception while executing OutputExpressionAction: Unable to cast object of type 'System.Linq.Expressions.InstanceMethodCallExpression1' to type 'System.Linq.Expressions.ParameterExpression'.'

The error occurs specifically in the expression: "Expression": "input2.FirstOrDefault(x => x.fullName != null);"

We would greatly appreciate any insights, suggestions, or guidance on how to resolve this error and successfully execute the second rule's expression.

Thank you in advance for your assistance.
Best regards, Amina

Reproduce the failure using the supplied workflows and C# snippet, starting at ExecuteAllRulesAsync and the OutputExpressionAction error. Compare the first workflow's output with the second expression using input2.FirstOrDefault; done means the second rule executes without the InstanceMethodCallExpression1 cast error and returns the intended result.