We use form links within PDFs as part of our training programme promotions. Sometimes potential customers get error messages like the one below. Other people can access the form ok.
Could it be to do with firewalls within their organisation corrupting the URL?
It seems to be a problem with the link originating from a PDF (yes the right address has been embedded) - but is usually only a problem for some people on large networks e.g. local authorities / councils. Really hope you can help!