One or More Signatures Have a Problem in Foxit PhantomPDF

Sometimes this can apply to multiple signed documents and signatures may intermittently not appear. The error may or may not appear in Adobe Acrobat Reader or Adobe Acrobat Pro; but if they appear in PhantomPDF but not Adobe, it is a good indicator of this being the issue.

The following articles should resolve this issue: 

• How to Automatically Trust Digital ID for Digital Signature

• How to enable Automatic Foxit Approved Trust List updates