Hey everyone, love this forum, received incredible help already a few times. 

Ran into a strange problem, as of yesterday when I click on contacts in Lightning my list view shows up like always, but when I click on a specific record, the lightning record page come sup blank. Literally nothing. I checked the setting and the specific lightning record page I created is the default for the org. Any idea what's going on?

I'm trying to better understand how field level security works with fields being required through page layouts. It seems there are 4 ways, you can make a field required:
1. When you create the field, you can tick the box to make it required
2. Through the page layout by clicking on the spanner/wrench next to the field
3.  Go to the object - Fields, click on the field name (not edit or del) and you can select "required"
4.  Go to Security Controls | Field accessiblilty, select the object, then the field and then you can edit through field access
What's confusing to me is field level security makes me think this is what you would use to make a field required, but it only allows you to select 'Visible' or 'Read'.

This came from trying to answer this question:
A custom field is made Read only from the Field level security and Required from Page layout. The Field will be?  
A. Read Only for the User
B. Required for the User
C. Throws an error and don’t allow to make Read only field Mandatory from page layout
D. User is given a choice in a pop-up window

The Quiz gave the answer as A, but I tested it and find the answer is B.
Would appreciate any input on whether i'm understanding all this accurately - thank you!