Checkboxes no longer working

We found out this morning that users are not able to see or select values in Checkboxes. Does anyone knows what is causing this?

Andrew, can you provide more info?  Maybe a screenshot or two.  Anything in the Developer Console?  Do you have any snippets or Action Framework at play?

Is it all users or just some users? Can a system admin see checkboxes?

Thank you everyone, I found out that our developer had added a css class to disable checkboxes. We removed that and everything works fine now.

Thanks for letting us know what was going to on!