$ tar -ztvf jetty-distribution-9.3.5.v20151012.tar.gz | grep -E "\.war"
-rw-r--r-- joakim/staff 858295 2015-10-12 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/async-rest.war
-rw-r--r-- joakim/staff 60893 2015-10-12 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/test-jaas.war
-rw-r--r-- joakim/staff 63245 2015-10-12 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/test-jndi.war
-rw-r--r-- joakim/staff 478055 2015-10-12 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/test-spec.war
-rw-r--r-- joakim/staff 908339 2015-10-12 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/test.war
-rw-r--r-- joakim/staff 884955 2015-10-12 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/xref-proxy.war
$ unzip -l jetty-distribution-9.3.5.v20151012.zip | grep -E "\.war"
858295 10-12-2015 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/async-rest.war
60893 10-12-2015 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/test-jaas.war
63245 10-12-2015 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/test-jndi.war
478055 10-12-2015 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/test-spec.war
908339 10-12-2015 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/test.war
884955 10-12-2015 15:41 jetty-distribution-9.3.5.v20151012/demo-base/webapps/xref-proxy.war
Where are you seeing that specific error?