The Nubus could be accessed but the data being transferred was bad. The error indicates a hardware problem.
Details
The main circuit board of your Mac contains a bus known as the Nubus. The Nubus allows you to add circuit cards to your system for enhanced functionality. The information being exchanged between the Nubus and a card you have added is bad.
What to do
You may have to replace the entire main circuit board of your computer to fix this problem. But first, remove all of your Nubus cards. Then add them back in one at a time and restart your system after adding each card. If only a card is bad, you should be able to identlfy it using this technique and avoid having to replace the entire main circuit board of your system.
