So are you suggesting putting my entire Max 5 folder in the File Preferences search path? I must be misunderstanding you because that leads to the very problematic situation of having Max 6 seeing both Max 5 and Max 6 versions of every Max Object.
That's strange to me that it runs fine for you. Are you on Mac or PC?
I have two different MacBook Pros (2008 and 2012 Retina) that I've tried running it on, both with Max 5 and Max 6 installed. In fact I've had the patch running in both Max 5 and Max 6 simultaneously on each computer with the exact same result. The issue is that the resulting image in Max 6 is blown out as if there is an additive video feedback loop in the process.
Attached are screenshots from both of my computers that shows the unexpected behavior.