code error need to check

public void Execute(IServiceProvider serviceProvider)
{

IPluginExecutionContext context = (IPluginExecutionContext)serviceProvider.GetService(typeof(IPluginExecutionContext));
ITracingService trace = (ITracingService)serviceProvider.GetService(typeof(ITracingService));

IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId);

try
{
trace.Trace("Inside try");
Entity target = (Entity)context.InputParameters["target"];
//Inheritance OBJECT

EntityReference regardingCaseRef = target["regardingobjectid"] as EntityReference;
Entity regardingCase = service.Retrieve(regardingCaseRef.LogicalName, regardingCaseRef.Id, new ColumnSet(true));
QueryExpression qeRelatedTasks = new QueryExpression("incident");

qeRelatedTasks.Criteria.AddCondition(new ConditionExpression("regardingobjectid", ConditionOperator.Equal, regardingCaseRef));

EntityCollection allRelatedTasks = service.RetrieveMultiple(qeRelatedTasks);
bool AreAllRelatedTasksCompleted = false;

trace.Trace("Case title: " + regardingCase["title"]);
// update case description = all tasks completed
Entity incident = new Entity("incident")
{
Id = regardingCaseRef.Id
};

incident["description"] = "All Task Completed";

service.Update(incident);

}
catch (Exception ex)
{
throw (ex);
}

}

public bool AreAllRelatedTasksCompleted(EntityCollection relatedTasks)
{

if (relatedTasks.Entities.All(x => ((OptionSetValue)x["cos_csutaskstatus"]).Value == 769190000))
{
//Console.WriteLine("All task completed");
return true;
}
else
{
return false;
}
}
}