When running Aqua Data Server v15.0.0 with java 1.7 

Admin > "System Settings" page generates an http 500
attached as "admin - system settings - http 500 - java 1.7"

Admin > "Email Queue"
a blank white page with no error
attached as screenshot "admin - email queue - white blank page - java 1.7"

Admin > Projects
create a project and immediately use the projects dropdown at the top right of the page
or click on a project link from the Admin > Projects tab
attached as "admin - projects tab - http 500 - java 1.7"

It is possible to enter a project by clicking a link for it in the /app/home and using any link for it except the Workspace link.
Workspace link produces http 500
attached as "admin - app - home - project - workspace link java 1.7"
attached screenshot illustrating which links work "project links that do not work from app home"

Inside a project I can create xjs files, add a server under servers tab, upload user files without issues