| Home Page | Recent Changes | Preferences

Crashing UnrealEd

Common UnrealEd Crashes: Easily Avoidable Tragedies


  • Don't put lights into the solid space because it will cause crashes.
  • At least on Win2K Pro, right-clicking on the desktop and changing Appearance → Schemes will crash the editor.
  • Don't try to run UEd 2 and UEd 3 at the same time, most likely all hell breaks loose. (Or one of them just crashes. ;))

Foxpaw: Interestingly enough, another part of the Wiki recommends doing this for porting maps from UT to UT2K3.

RDGDanClark: It's not a set-in-stone guaranteed crash situation. I often have both open with no problems at all. I suspect it's got to do with the hardware/software configuration on induvidual machines - a few minor differences can mean up or down sometimes.

  • When setting the Light Color (Button in UEd 2) don't click on any of the viewports. If you do, the Editor will crash.

Brushes and vertices

  • When you are vertex editing be careful and don't cross the edges of polygons and don't overlap two or more vertices. If you overlap the vertices you won't be able to separate them afterwards and if the overlapping reduces the facecount of the object then UEd will instantly crash after you release the mouse button moving the vertex.
    • Save a lot when you are using the BSP based terrain brush.
    • Keep a close eye on what you move and where
    • If you are using the Vertex mode the sensitivity of the movement depends on the grid setting you use. Certain grid settings will need a steady hand and lots of concentration.
  • Don't try to select a surface's underlying brush with SHIFT+Left-Click if the brush has been deleted (see Mouse Control for more on this function).
  • Don't duplicate a brush that's smaller than the current grid size, or equal and off-grid.

2D Shape Editor

  • Don't cross edges in the 2D Shape Editor. When you try to extrude the shape UEd will crash.
  • UnrealEd 2 can be crashed by importing a texture file into the 2D Shape Editor incorrectly (and, this happens unexpectedly). When you open the 2D Shape Editor and attempt to import a door texture with the intent of transferring the exact dimension to a 3D Brush, you can crash UnrealEd by doing 2D Shape Editor Menu → File → Image → Get From Current Texture. The behavior of the 2D Shape Editor is inconsistent, sometimes the above mentioned technique works, sometimes it doesn't. (This suggestion from Machismo) The solution is that the 2D Shape Editor can only open .bmp textures. So, when you have the desired texture selected in the Texture Browser, right click the texture and select, Export to .pcx. In the Save Dialog window, select, Save as Type > All File Types, and save the file as a (unique name) .bmp file. Then, from within the 2D Shape Editor, select, 2D Shape Editor Menu → File → Image → Get From Disk and, import.

Tarquin: I've never had this problem, some people say it's frequent. Could it be OS-related? I've just seen a post on TO about this occuring after a switch to win2k.

Daemonica: I don't think it's Win2K, a few of us use it here with no problems, it's a useful and often used tool.

Legal: I don't get it with UED2 but with 3. It must be teh G0bl1n :p


  • If you delete a texture that is in use UEd will crash. Fix: use the Texture Replacement Tool before deleting a texture. (Despite you don't see the texture it might be used on a not visible surface of a brush.)
  • There are several ways to crash UED if you are not careful when deleting or renaming textures, they are:
    1. Deleting a texture that is in use - if you delete a texture that is in use, UED will crash if you try to save or look at the texture in the 3D view (this is really tough, you're moving around and all of a sudden it hangs). The correct way to do this is to first make sure that the texture is not in use Anywhere in the map (including surfaces you can't see!), and then delete the texture. If you have used the texture a lot and are not sure where all it is, then you can use the texture replacing tool, or test if you have gotten rid of the texture entirely by performing a texture cull, which will also remove the texture for you.
    2. Delete a texture and then rename another texture to be the deleted texture's name - I'm not quite sure of the specifics, but if you want to do this delete the old texture, save, and re-open the map, then rename the other file. Better yet if you are simply replacing a texture import the new one right over the old one.
  • Importing a file of .bmp or .pcx type that is NOT in indexed 8-bit color format will crash the editor with a General Protection Fault. (I'm not sure you can actually save a .bmp in RGB color mode or anything else besides indexed but I know for a fact that Photoshop is quite willing to save a .pcx in RGB color mode).
  • In UnrealED 3, many time importing a texture with the same name, overwriting a previous texture, and then using the same type of DXTC compression to compress the texture gives a crash. Possible workarounds would be compressing the texture before importing.
  • This won't crash UED, but it'll make your map completely unplayable, saving the MyLevel package as a texture package, or SM package, etc. So far i have found n remedy for this.


  • Adding a modified AmbientSound to your level, when the file size becomes too big for the Unreal Engine (Can this be accurately quantified?) will cause both Unreal Tournament and the Unreal Editor to crash. Typically, this is a file mixed with ModPlug Tracker and converted to .wav format. (I will add a better explanation later)
  • Adding a custom sound to your level without importing it properly ( and, I don't know the correct technique for this) will cause a General Protection Fault. The level design will then be unplayable, even if you delete the Ambient Sound. The recommended techniques in various tutorials, does not work as advertised. (I will research this and find the TRUTH.)

BSP Rebuild Options

  • Which settings in the Build window can safely be changed?
    • Anything in the Optimization section. Avoid at all cost the BSP Rebuild Options section. People have completely killed UnrealEd by changing these. (This seems to be what everyone quotes, but you can quite safely change the sliders without destroying the editor. They are also set back to the default settings when you next load UED, so you can just reload the editor if anything goes wrong)
    • Changing the first slider alters the amount of BSP cuts that are made. I don't know the exact effects of this, only that setting it to the highest level gives a ridiculous amount of BSP cuts and setting it to "Minimise Cuts" does exactly that. Mess with it a bit if there's a BSP error that you absoloutly can't get rid of, or lower this slider if your node count is far too high.
    • The second slider adjusts how zone portals are handled when rebuilding bsp. Very rarely, a zone portal won't zone off an area, even if it completly seals it. Setting this slider closer to the "Portals cut all" option should fix this problem. Setting the slider to "Ignore Portals" will increase the chance that the ed won't zone an area off (don't know what the point of that is)


Whenever I set all the rendering options in advanced properties to true and then select show all actors, the editor runs fine until i move the camera through a wall and outside of the level, it then jams and when i close it (with Ctrl, Alt + delete) i get an error in different parts of the level. –ProjectX

Daid303: Creating an inline object in the Default properties of any actor in the Actor browser also gives a GPF.

Wormbo: Don't try to create an Emitter that emits particles with high acceleration values and lifespan. UnrealEd will decide to eat up more and more memory (more than usual) and doesn't respond anymore.

Category Mapping
Category Troubleshooting

The Unreal Engine Documentation Site

Wiki Community

Topic Categories

Image Uploads

Random Page

Recent Changes

Offline Wiki

Unreal Engine

Console Commands


Mapping Topics

Mapping Lessons

UnrealEd Interface


Scripting Topics

Scripting Lessons

Making Mods

Class Tree


Modeling Topics


Log In