In Acrobat X, File/Properties/Security/Doc Restrictions Summary, Document Assembly needs to be allowed on signed

Also, I do not have a password for my signature.

Is the recipient using Adobe Acrobat?

Are you using a digital signature that has a digitally encrypted certificate that has a public and private key or just a facsimile stamp?

When you sign your PDF, do you specify 'Lock after Signing' in 'Sign document' dialogue box. As that would lock the PDF down and restrict you from making any changes.

Alternatively if you draw a signature field before hand, make sure in the signature field properties, under the 'Signed' tab is set to 'Nothing happens when signed', this will prevent it from being locked down.

Just to check, when you say 'Document Assembly' do you mean extracting pages, as the above method allows this but is there other things that you are trying to achieve.

Hope this helps?

Hi,
Unfortunately there is nothing you can do about stripping out the signature when combining files or extracting pages. Why this is is because what you are effectively doing is invalidating the signature, the signature wants nothing to do with the combined files so it will remove its signature as you are adding content that the person who signed did not agree to and sign off. If you want to keep the signature intact and combine files, you would have to use Acrobats portfolio option.

The option i previously mention was if you drew the signature field from the Edit forms menu, and not the place signature like you was doing. You have more control if you add in the signature field from the 'forms' section.

If you still want your sigature on the combined files, you will have to get the PDF back, and sign it again.

Hope this helps?