Walkthrough crashes in General Discussion Posted July 25, 2002 Matthew, Thanks for your further assistance. I am indeed getting the message "A required resource was missing" as the program freezes. To reproduce the problem: open a new document, extrude a rectangle, set any sun position, set a perspective view, render using OpenGL, start to navigate using the walkthrough tool. After about 30 seconds the speed of motion begins to slow noticeably. After another 30 seconds, multiple redraws of the sun icon begin to appear, then a confused screen appears, and then multiple recurrences of the "A required resource" message, then the appearance of the complete message "A required resourse was missing." At this point, if you wait, you may regain a semblance of normal program function (except that the walkthrough tool will cause a freeze immediately). However, VW then operates slowly and erratically and affects the performance of any other program until VW is shut down. It is not necessary to restart the computer in order for it to function normally. The full specs on my video card are: 64MB DDR NVIDIA GEForce4 MX 420 (TV out)BIOS version: 4.17.00.45.42Driver .dll's are all 184.108.40.20611 Thanks - any solution to this problem would be appreciated. I could install an old version of VW 8.5 I own, if you think that might work. However, the firm's principal might then want to return the new copy of 9.5.2 for a refund!