SCVMM 2012 R2 Admin console keeps crashing and won't open

SCVMM 2012 R2 has been working fine for the past 3 weeks.  2 days ago the admin console crashed and now when I try to open it, it just crashes and is in a crash loop.  It won't open.  I get a debug error that has "CLR20r3" in it and an event log with "NullReferenceException" in it. 

Any help would be great

Thanks