So when you try to register or login on internet explorer or very old firefox it doenst work

I applied a custom skin [https://github.com/specialattack/phpbb-subsil … ag/phpbb-3.3.10]
So the webpage doenst load like a weird gumber on ie 6, 8 and 11. However...

Do you know how to fix logins + register?
On ie8 and 11 for example you cant get past the register agreements form. Pressing agree generates a new &SID= and just reloads the page.. And logging in says form invalid. [on ie 11 it works if u press the login button instead of enter, but you cant log out anymore]
This happens on register 9/10 times, very sometimes it works
Seems to be with cookies. Any idea?
im using 3.3.15
i can provide my discor for easier comms

chatgpt said using an older version of phpbb is risking security. do i really have to use other software? minibb for example uses my raw vps in every hyperlink, an dthe domain times out most of the time for some reason