I just tried this in Vue 4.06 and windows 98se, and had no problems. I tried turbulence and rotation, saved and re-opened and rendered ok. I've been doing some complex material animations recently, and had no problems, but this doesn't mean you haven't found a bug. What operating system do you have, and what version of vue? Have you tried this in a separate and new test file. If the test file works then you have a corrupt original file. This happens occasionaly, so always keep loads of backups and do a 'save as' every time you do anything major to the file. I often end up with 30 or forty versions in the end, and only delete them when theh project is finished If the test file crashes in the same way, let us know more details of os and version etc - if you want to send me a small test file let me know - I've got win 98 and 2000 here.