Invalid signature error message

I am trying to sign a PDF using credentials stored on a smartcard. The same process worked a few weeks ago for a different document. But, now when I try to sign anything, I get an error "At least one signature is invalid". The reasons listed below the error are: Document has been altered or corrupted since it was signed, Signed by current user, Signing time is from the clock on the signer's computer.

I get the same error when using Reader or Pro.