Unity crashes while loading small assets

I am working in Unity 4.5.2 with Windows 8.1, and am using Perforce for version control. Several times now, when I've synced with the depot and opened Unity, Unity stops working and closes when it is re-compiling scripts and assets. This will happen every time I try to open Unity after (but not if I start a new project). The only solution I've been able to find is wiping my files and re-downloading them from the depot. I looked at Library\FailedAssetImports.txt to try to figure out what assets may have been causing the problem, but there doesn't seem to be anything special about the assets it reports. If I delete the one that fails, a different one will fail. Assets that fail include ones from ProBuilder, uScript, UFPS, and Standard Assets. Below are some of the ones that have failed:

 Assets/ProCore/Shared/Resources/GUI/ProBuilderToggles/ProBuilderGUI_trigger-on.tga
 Assets/uScript/uScriptEditor/Editor/_GUI/uScriptDefault/elements/uscript_node_event_socket_out_variable_vector3_selected.png
 Assets/uScript/uScriptEditor/Editor/_GUI/EditorImages/LightSkin_Underline.png
 Assets/Standard Assets/Skyboxes/Textures/StarryNight/StarryNight_back.tif
 Assets/ProCore/Shared/Resources/GUI/ProBuilderToggles/ProBuilderGUI_trigger-on.tga
 Assets/uScript/uScriptEditor/Editor/_GUI/EditorImages/LightSkin_Underline.png
 Assets/uScript/uScriptEditor/Editor/_GUI/uScriptDefault/elements/uscript_node_event_socket_out_variable_vector3_selected.png
 Assets/uScript/uScriptEditor/Editor/_GUI/uScriptDefault/elements/uscript_node_default_socket_out_variable_float_connecting.png
 Assets/uScript/uScriptEditor/Editor/_GUI/uScriptDefault/elements/uscript_node_default_socket_variable_gameobject_connecting.png
 Assets/uScript/uScriptEditor/Editor/_GUI/EditorImages/DarkSkin_ListViewColumn-N1.png
 Assets/UFPS/Base/Content/Levels/DemoScene1/Textures/LightmapNear-0.exr
     

I suspect that these particular assets aren't the real problem, but rather that some underlying thing is breaking. Maybe something got corrupted?

If anyone has experienced this problem or has any advice, it would be much appreciated!