[Richard]

I've installed 1.7.1 in the last week and need to uninstall it and wind back to the last stable 1.5.1. I can't export from SU without crash and cant work in studio without random all black renders.

Is there likely any issues going back from 1.7.1 to 1.5.1?

I had to do the same from 1.6 previously and did end up having a few small issues, though nothing like I'm currently having!

[Bubbaloo]

Some materials won't work, your 1.7.1 MXS files won't open.

[Richard]

Thanks mate thats a bit of a bummer! I had imagined there might be at least some issues!

[Bubbaloo]

Probably more that I haven't thought of!
Have you had any luck posting in the SU forums? JD's usually on top of things.