It seems you are the only one with this compatibility issue, so perhaps you should find an alternative to Tor-Browser since it blocks Java applications.
I sympathize with your situation, but consider that after taking an opinion poll, Ken graciously spent $285 to renew a one-year license for this chat room. Unless you can convince the majority to revert back to the old one, and reimburse Ken the time and money spent, I see no logic to revert back to the old chat room because of one user's (avoidable) compatibility issue. I understand your frustration, but consider the bigger picture here.