Hi Ariel:

I think the problem is you are running Tomcat 8.5, which is currently unsupported.
Just yesterday we updated our Supported Technology page, which does not include Tomcat 8.5.
See the docs here:
https://www.labkey.org/home/Documentation/wiki-page.view?name=supported

The latest Tomcat version that is currently supported is 8.0.x.

Thanks, Steve