So this error is making a lot of TF2 players not having fun because the crash that follows shortly after this error. Basically, every entity (except func_details) goes invisible. Player models, props (dynamic or static), map particles, weapon particles, everything. Then it's only a matter of time: either the game crashes after 2 seconds or you're stuck playing on a map that, apart from world geometry, is completely invisible. Only shadows show, both the ones baked upon compiling and the player shadows. A good example is this image captured by me today, after it happened and didn't crash the game. Notice how the 3D skybox is unaffected (the tower is 3D skybox) and how decals remain unaffected as well, and as long as almost the whole map is invisible the CUtlLinkedList overflow! (exhausted index range) message is spammed in the console. After some digging around on the interwebz I found out it's an old issue relating to entity count. Some people traced it back to a memory leak, but after some research done be yours truly I found nothing resembling it. TF2 is not the only Source game to have the issues, Dota 2 and CS:GO had it as well. However, the entity count thingie is strange. If it appeared only on custom maps it'd make sense. Too many entities=game crash. However it's now happening on stock Valve maps as well. Couple of examples include but are not limited to Dustbowl, Barnblitz, Thunder Mountain, etc. So my question for the people here is this: has Valve inadvertently made changes to the max entity count? Has anything weird happened to the whole entity system in general? The time frame is fairly small: it started happening after the January 30th update, which, and here comes the irony, was supposed to fix this very issue in the first place, with Valve relating it to the particle system. EDIT I've emailed Valve about it and the next update for TF2 should fix it. Nevermind.