Does your third party viewer crash? It could your texture file format.-- try this fix.

Spanki publishes this interesting tip on texture files in third party viewers other than Emerald, and why they may be crashing.

I use Imprudence now, and it has not crashed on me -- but others are saying that it does.

http://spankimoulliez.blogspot.com/2010/08/tip-for-third-party-viewers.html