Module 2 Milestone 1 not opening

I have completed till setup 4 of module 2 and marked as complete but the milestone 1 is not opening. It has been half an hour now.

Refresh the page, if the module is not unlocked till now. Then do ctrl+shift+R to clear all the cookies then reload the page, login into then your module might get unlocked. You can still complete all the modules. See the queries other people faced in subsequent modules and complete this ME.