It's the same for me. The APU on my ZIBO 737 won't start; what could be the cause? I reinstalled a clean version of Zibo Windows 12 (4.05), but it still doesn't work. I disabled all the plugins, but that didn't help either. After reinstalling B738X_XP12_4_05_35, Noop! And does anyone know how to fix it? Thanks in advance for your help.