Yesterday I reported to Steam Support that problem with the model viewer crashing out Hammer (http://forums.tf2maps.net/showthread.php?t=7379). Here's my bug report: Opened Steam SDK to continue working on my TF2 map. It updates. Now ever time I use the model viewer in Hammer it shuts down Hammer immediately. Sometimes I wish they'd just leave things alone. How do I send a bug report? How long will this probably take? Today, guess what? Steam gets back to me and tells me this: Hello Carter, Thank you for contacting Steam Support. We do not offer technical support for development tools or user made content. Please visit the following page for information: Title: Resources for the Source SDK, Mapping, and Dedicated Servers Link: http://support.steampowered.com/kb_article.php?ref=1987-WYGJ-3701 Additional resources can be found on our forums: http://forums.steampowered.com Also, feel free to visit the Valve Developer Wiki: http://developer.valvesoftware.com/ So guess what? All of you people who think the model viewer is crashing Hammer, you better understand that it isn't the model viewer that's the problem. It's you not knowing how to use Hammer.