(Note: Split by JasonJAyalaP from original Support topic)
( https://forums.whonix.org/t/cant-fix-i2p-no-longer-works-with-the-latest-tor-browser )
I think the way to support (or to use) I2P is to add a simple separate browser, like Firefox (or Iceweasel)
It should be configured for I2P proxy settings, any other connection should be blocked (may include internal settings and firewall) and also I2P outproxies should be deleted so the fingerprinting problems will not occur since all connections would be made inside I2P which share the same user agents with other users.
The next step is to add NoScript and block all by default as an extra caution. “Never remember history” would be the last configuration.
Outproxies are not useful anyway, one should use Tor to browse the outer web anonymously. Very few people or nobody may need outproxies with the current design.
And I should add it’s not a good idea to combine i2p and tor browsers.