Face Fillet Error

Hey guy,


I'm struggling to create a face fillet on a part:

However I have been able to complete the operation on a very similar part:

The fillets are vital as they help create a solid structure when printing out. Without the fillets I found the blade very susceptible to snapping at the join to the central structure.


Where am I going wrong and what is it that is causing this error?

SolidworksDrawings And Detailing