https://www.epo.org/en/service-support/faq/law-practice/oral-proceedings-held-videoconference/conduct-oral-proceedings-5

What happens if my connection or reconnection fails?

Prior to the proceedings, the parties will be asked to provide a telephone number to be used during the VICO in case technical issues arise.

The EPO will keep connection details as communicated by the parties as non-public information and they will not be exchanged through the chat.

At the beginning of the proceedings, the chair may also provide a telephone number for contacting the division.

If your connection/reconnection fails, the division will contact you by phone. Alternatively, you can send an email to the division or call them. Technical support will be on hand.

Where, notwithstanding all efforts of the participants, technical problems prevent the oral proceedings by VICO from being conducted, a new summons to oral proceedings will be issued. As a rule, such new oral proceedings will be held by VICO, unless there are serious reasons for not doing so.