I second the Real World Bryce book too...it's not cheap thats for sure, but it's over 900 pages of info try www.amazon.com they usually have used books for sale for a few dollars off, do the search by "Bryce" in the software section... Now for your render problem try saving that render/file with a new name ...file is probably corrupt...just rename it and do whatever you wanted to fix then do your render...also try this.... the "big red ball" render button, just to the left of it, is a smaller button....press that, then press the render button should speed things up here's a helpful item.... at www.vtc.com they have training programs (movies that play, with an instructor talking too) for tons of software programs....one of them is Bryce 5 they offer the first 3 chapters free just need to download and watch ...the free stuff will get you a lot farther then you are now ....I would suggest a monthly subscription for $25.00 ....but the book ( Real world Bryce) is more in depth