https://www.epo.org/en/node/specifics-oral-proceedings-4

What happens if I cannot comply with the technical requirements or I am not able to install the necessary software? Would the proceedings then be held on the EPO's premises?

Sweeping objections to the reliability of VICO technology or the non-availability of VICO equipment do not normally qualify as serious reasons for the proceedings to be held on EPO premises. If it really is not possible for a party to meet the technical requirements for participating in a VICO with the EPO, a request for oral proceedings to be held by way of exception on the premises of the EPO should be filed as early as possible together with detailed reasons. The granting of requests for oral proceedings to be held on the premises of the EPO is at the discretion of the competent division.