# "Accurate Velocities from Vertex Deformation" crashes in Lightmap Density viewmode **URL:** \ **Category:** Platform & Builds\ **Tags:** rendering-system, viewport-bugs, unreal-engine, bug-report, question\ **Created:** [September 30, 2015, 8:18am UTC](https://forums.unrealengine.com/t/accurate-velocities-from-vertex-deformation-crashes-in-lightmap-density-viewmode/333858 "2015-09-30T08:18:34Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![Tim\_Hobson](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Tim\_Hobson](https://forums.unrealengine.com/u/Tim_Hobson)\ **Post date:** [September 30, 2015, 8:17pm UTC](https://forums.unrealengine.com/t/accurate-velocities-from-vertex-deformation-crashes-in-lightmap-density-viewmode/333858/2 "2015-09-30T20:17:28Z")
Hi Daniel, Can you provide more information on what you’re setup is and how you’re able to reproduce this crash? Any steps for what you’re doing before the crash that causes this or a sample project that does this would help as well. When the editor crashes, is there any Windows error windows that pop up as well? If so, this may be a crash within Windows. Follow the instructions here for the Windows Event Viewer to see there is an error log that may be useful. > **[A new, community-hosted Unreal Engine Wiki](https://forums.unrealengine.com/t/a-new-community-hosted-unreal-engine-wiki/141494)** > > After over a year in maintenance mode, the official Unreal Engine Wiki is now permanently offline. These resources now live on a new community-run Unreal Engine Community Wiki — https://unrealcommunity.wiki/! You will be able to find content from... Also, please attach your DxDiag here as well. Thank you! Tim --- _[View the full topic](https://forums.unrealengine.com/t/accurate-velocities-from-vertex-deformation-crashes-in-lightmap-density-viewmode/333858)._