I was dealing with the same issue.
I opened up the jar and found the views folder was buried and extra folder deeper than we're expecting. Should work long enough until they fix it in the next version.
Quick solution that worked for me:
#extract folder
jar xfv logstash-1.1.11.dev-flatjar.jar logstash/web/views
#move files around
cp -r logstash/web/views/views/ logstash/web/
rm -rf logstash/web/views/views
# push files in jar
jar uvf logstash-1.1.11.dev-flatjar.jar logstash/web/views/