Having trouble using the Mobile Portal?
1) Go to "http://www.infinitecampus.com/mobile"
2) Scroll down and click on the FAQ link which will take you to http://media.infinitecampus.com/public/html/mobile/faq.html
3) Read over this FAQ page
4) If there are still issues scroll down to the bottom of the FAQ page and look for [Support Request - Having a problem? Drop us a line and let us know by submitting a support request] and click on that link.
5) This takes you to a form for submitting questions/issues/bug reports for the Mobile Portal app.
(the link to the form is https://g3.infinitecampus.com/mobile/supportRequest).
One good place to start is to uninstall the app and then reinstall it again, and then try again. They could also delete their cache and temp files if possible and re-try.