Please contact the file manager of the office directly and not via the mail from "firstname.lastname@example.org".
Please provide as much information as possible so that it can be properly investigated:
- error message that appears
- time of attempt to sign + signing method (eID/itsme/SMS/E-MAIL/Manual)
- type of device (desktop, notebook, smartphone, tablet, ...)
- operating system type (Windows, Mac, Linux, Android, iOS, ...)
- browser type (Google Chrome, Firefox, Safari, ...)
- name of PDF application (Adobe Reader, Foxit, Edge, Google Chrome, ...)