Google APIs Explorer “Timeout while fetching” in Development Server with appengine 1.8.3 SDK

Google APIs Explorer "Timeout while fetching" in Development Server with
appengine 1.8.3 SDK

Im creating a project in google app engine. While testing the project in
development server I have encountered these error.
{
"error" : {
"message" : "Timeout while fetching:
http://127.0.0.1:8888/_ah/spi/com.xxx.XXXEndpoint.method",
"code" : 404,
"errors" : [ {
"domain" : "global",
"reason" : "notFound",
"message" : "Timeout while fetching:
http://127.0.0.1:8888/_ah/spi/com.xxx.XXXEndpoint.method"
} ]
}
}
I dont know if these error are related to Fail to load endpoint class
Note i already apply fix in
https://code.google.com/p/googleappengine/issues/detail?id=9824 but its
not also working.