I have received a workbook with macros in it. I trust the sender and the
workbook is signed with a digital signature. However, I receive a security
alert informing me that the macros have been disabled because the signature
is invalid and cannot be trusted because the issue of the certificate cannot
be found. Despite installing the certificate and adding the document to my
trusted folders, I cannot run the macros in this workbook.

Any inpout would be greatly appreciated.