OGNL is used to call action's methods

[Alireza Fattahi]

I used below strategy for error manager:
All actions can throw exception.There is a Error Manager Interceptor which 
catch all exceptions and convert them to a json message and return it.        
try {            return invocation.invoke();        } catch (Exception ex) {    
             //Make some json result            
response.getWriter().write(String.format("{ \"%s\":\"%s\"}", 
DEFAULT_GLOBAL_ERROR_KEY, ex));
        return Action.NONE;     } 

This was working in Struts 2.3.16.
After switching to 2.3.20 this is not working. When an action throws an 
exception, I got below warning
DEBUG accessor.XWorkMethodAccessor   Error calling method through OGNL: object: 
[foo.LoginProcess@61d18d46] method: [result] args: [[]] 
I think it is because OGNL is used to call action's methods.  ~Regards,
~~Alireza Fattahi