How to install ODK on NAS SYNOLOGY

What is the problem? Please be detailed.
I am trying to install ODK on my Synology DS 216+.
I followed the manual: ODK on Synology Was ( ). But, I have this error: FAIL - Application at context path / ODKAggregate could not be started

Someone can help me!!!

What ODK tool and version are you using? And on what device and operating system version?
I installed Tomcat 6 and Java 8. I tried to install Java 7, but impossible

What steps can we take to reproduce the problem?
When I want to start ODKAggregate inn Tomcat interface

What you have you tried to fix the problem?

Anything else we should know or have? If you have a test form or screenshots or logs, attach here.