GWT failed to get the serialization policy

When I deploy newer version of my GWT application, I get sometimes this log error:

SEVERE: GwtRpcEventSrvc: WARNING: Failed to get the SerializationPolicy 'www.host.com:22041/MYAPP/'; a legacy, 1.3.3 compatible, serialization policy will be 
 a result.                                                                      

• Question 1) Is it a problem of serialization policy files remaining in browser cache?开发者_开发技巧
• Question 2) How to prevent such log message? I tried to add changing URL request param to nocache.js (<script src="MyApp.nocache.js?v=123"...) but it did not help.

Try clearing your browser cache. It worked for me.. after searching a lot of a lot of ways to solve it.

See:

• how to clear cache in gwt?
• Stop browser scripts caching in GWT App
• GWT Caching Concept

In summary: you need to set HTTP headers not to cache the .nocache.js files via your web server or a servlet filter