priiloader has nothing to do.
Boot the Wii, go to system menu, launch the Homebrew Launcher, select CFG Loader. (this way, there's no priiloader involved) and see if it works or not.
don't autoboot a homebrew from priiloader unless you know your setting is correct. First, setup your homebrew and usbloaders and be sure everything works fine from HBC without using priiloader's autoboot feature. only after all is good you can set autoboot feature.
if the autoboot in priiloader is the issue, you installed the wrong dol file.