at Microsoft.OData.UriParser.ExpressionLexer.ValidateToken(ExpressionTokenKind t)
at Microsoft.OData.UriParser.UriQueryExpressionParser.ParseExpressionText(String expressionText)
at Microsoft.OData.UriParser.ODataQueryOptionParser.ParseFilterImplementation(String filter, ODataUriParserConfiguration configuration, ODataPathInfo odataPathInfo)
at Microsoft.OData.UriParser.ODataQueryOptionParser.ParseFilter()
at System.Web.OData.Query.FilterQueryOption.get_FilterClause()
at Microsoft.Crm.ObjectModel.EdmModelEvaluator.EvaluateFilterExpression(String filterExpression, ODataQueryOptions queryOptions)
at Microsoft.Crm.ObjectModel.EdmModelEvaluator.EvaluateFilterExpression(String filterExpression)
at Microsoft.Crm.ObjectModel.CallbackRegistrationService.<>c.<.cctor>b__79_0(EdmModelEvaluator evaluator, String testValue)
at Microsoft.Crm.ObjectModel.CallbackRegistrationService.ValidateInputEntity(IBusinessEntity entity, ExecutionContext context, IFeatureDetailContainer featureDetailContainer)