Fill in & sign - signature block blacked out

Hello,

For some reason, now when I try to use the fill in and sign function, the signature block that I uploaded appears as a blacked out bar. 

When I click sign yourself it displays my signature, but when I go to place the signature in the document, the entire section is blacked out.

I've tried opening documents I've successfully signed in the past--the old signature appears correctly but if I try to add a new signature I get the black bar.

Thanks for any help/advice,

Erik F.