1 - add "bug_test" to ezpublish.yml
2 - make a login to any interface with an editor or administrator
3 - create a folder (on root) named "bug_test"
4 - click on the newly created folder
5 - verify the exception "TwigBundle:Exception:error500.html.twig"

(considering that the ezwebin_site as default site)
1 - login into ezwebin as "admin" (http://<your site>/)
2 - create a new folder named "ezwebin_site"
3 - click on the newly created folder "ezwebin_site"
4 - verify that you get redirected to http://<your site>/ezwebin_site
(that is in fact where we were before)
5 - click again no the newly created folder "ezwebin_site"
6 - verify that it opened the folder
7 - verify that url looks something like http://<your site>/ezwebin_site/ezwebin_site