Acrobat Reader signature plugin yellow question mark

[kevpWacom]

I am developing a digital signature plugin (primarily for Reader but should work in Acrobat as well). I have a basic proof of concept working, with signing and verification and custom signature appearance but I am getting a large yellow question mark displayed behind my appearance.

I have seen other posts on this forum which suggested the certificate needs to be trusted but I have done that and I still get the question mark.

What could I be doing wrong? What do I need to do to make the question mark go away?

(I am developing/testing with Acrobat Reader DC and a self-signed certificate on Windows 10.)

[lrosenth]

If you open the Signature panel, you should be able to see what the reason(s) for the question mark are…

[kevpWacom]

There's nothing obvious to me here - am I missing something?

[Guest]

Hi,I'm sorry to bother you.but this problem has trobled me a long time , that i load my plugin in adobe reader dc,then it will prompt ,tell me how to slove the problem please ,thank you

[kevpWacom · Accepted solution]

Answering my own question (with a little help from this forum and the good people at Adobe):

From the forum: "The multiple-layer model for digital signature appearances in PDF was deprecated and is no longer part of the ISO standard for PDF (ISO 32000-1)."

The default, kindly added by Acrobat/Reader, for the n1 layer, if I don't set anything, is that big ol' yellow question mark. The solution is simply to make layer n1 optional and the question mark goes away.