I'm trying to compile a project for iOS using Unity 4.3 and am getting the following two errors: BadImageFormatException: Format of the executable (.exe) or library (.dll) is invalid. Mono.Cecil.PE.ImageReader.ReadImage () Mono.Cecil.PE.ImageReader.ReadImageFrom (System.IO.Stream stream) Mono.Cecil.ModuleDefinition.ReadModule (System.IO.Stream stream, Mono.Cecil.ReaderParameters parameters) Mono.Cecil.ModuleDefinition.ReadModule (System.String fileName, Mono.Cecil.ReaderParameters parameters) Mono.Cecil.ModuleDefinition.ReadModule (System.String fileName) Mono.Cecil.AssemblyDefinition.ReadAssembly (System.String fileName) UnityEditor.AssemblyReferenceChecker.CollectReferences (System.String path, Boolean withMethods, Single progressValue, Boolean ignoreSystemDlls) UnityEditor.AssemblyReferenceChecker.GetScriptsHaveMouseEvents (System.String path) UnityEditor.HostView:OnGUI() ...and... !IsDirectoryCreated(kManagedDllsFolder) UnityEditor.HostView:OnGUI() The project was compiling fine yesterday, and I haven't made that many changes today. I've tried reinstalling Unity and deleting the /Temp folder, as well as changing the Api Compatibility Level from .NET 2.0 Subset to .NET 2.0, but nothing seems to work. Does anyone have an idea? I'm going nuts and would appreciate the help.