I have installed adobe acrobat standart DC. From TOOLS, CERTIFICATES, TO SIGN FOXGLOVE the document.
On having updated ADOBE ACROBAT STANTART DC version 15.016.20039 already we cannot sign.
So what is happening exactly. Describe your workflow in details: all the clicks, user interactions, dialogs and alerts that you get.
What is Foxglove? I do not think it is a part of Acrobat. Perhaps it is a part of your workflow.