Well.. I found where is the problem. Doing many deploys as declarations in *web.xml*, I could identify (* step-by-step*) which configuration was breaking the backend instance startup.
I could certainly, for sure, isolate this declaration: <servlet-mapping> > <servlet-name>Faces Servlet</servlet-name> > <url-pattern>**.html*</url-pattern> > </servlet-mapping> Experimenting changing **.html*, to **.jsf* *and, *later to **.xhtml* resolved the problem. Changing back to **.html* broke it again. I would guess something related to the startup request path (_ah/start/), but I can't assert nothing. I hope it help someone.. -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine-java/-/AH4kg867LDoJ. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
