EAR generated using ANT doesn't work on Websphere 8.5

EAR generated using ANT doesn't work on Websphere 8.5

The object is to build .ear by using ANT then deploy it on Websphere 8.5
with wsadmin.
Manually, the ear file is generated from a jar file and after deployment,
the web application works very well.
But if I use the ear generated by ANT, after deployment (by hand or by
wsadmin), I always have this error :
SRVE0255E: A WebGroup/Virtual Host to handle /WebApp$%7Blogout.url%7D has
not been defined.
SRVE0255E: A WebGroup/Virtual Host to handle localhost:9080 has not been
defined.
Someone knows which might invoke this problem. I met this message before
while my colleague deploy on websphere with a war file directly from a
Tomcat server.
Thanks in advance.