Material editor slots black

[Neilg]

I've read through everyone elses issues with this and none of them seem to be quite the same problem.

If I open a blank scene, the mat editor/local rendering works fine.
If I open any previously saved scene the mat editor slots go black, and local renders dont work (nothing comes up, just clicking the render button doesnt do anything)
Network renders work fine
If I switch the renderer to scanline or mental ray the material editor slots remain black and rendering still doesnt work.
If I reset or start a new scene the problem continues, with scanline and mental ray too. This is whats throwing me off about other peoples licensing problems.

The vray render settings are still visible during this too, at no point does it mention any licensing issues.
It started last week, but would only start happening after i'd opened/closed 3-4 scenes. Now it does it on the first scene I open. Size or complexity doesnt have an impact here, tried it on some incredibly light early scenes.

Tried new graphics drivers, switching to open gl too.

I'm on max2009 with vray 1.5sp4a
It doesnt do it at all in max 2010 or 2011, but this project has to be done with 2009.

Any ideas? I'm stumped

[Deflaminis]

What happens if you merge the corrupt scene into a brand new one that doesn't have this problem?

[jacksc02]

have you tried resetting your material slots?

[prateekvishwa]

this is probably because you opened your file without launching Vray license server. It should be launched before you open your file in 3ds max.. Closing 3ds max, launching server, starting 3ds max & reopening scene should solve this.. Good Luck!

[Neilg]

Deflaminis - same thing
jacks02 - yeah, no change
prateek - thats not the issue, the licenses work fine at first. It acts like it drops it - but it affects scanline and mental ray from then on out, so it doesnt seem to be a vray specific issue.

It's not fixed, but i'm working around it ok.