Can't install system menu 4.3U on PAL Wii

I have changed my Wii consoles region to USA/NTSC and installed system menu 4.2U with dop-mii but I can't install 4.3U via the wii system menu (Error 32004) or dop-mii I get an instant DSI error page.

Priiloader settings for blocking updates are all disabled so I have no clue whats causing this. Any help?

Make sure you've installed the IOS that 4.3U runs on. Not sure which one that is, but find out and install it. After you do that, try to install the 4.3U menu again.