I’ve been having quite a few problems with Unity 3.1 compared to 3.0. Currently most of the scenes in my project crash on Play in the editor. It immediately exits.
Anyone else noticing this problem?
If I run one of the few scenes in my project that doesn’t crash the editor, and then try to open a scene that would crash the editor if I were to run it, opening the scene itself crashes the editor.
I get a bunch of exceptions like this when I open my project, not sure if its related to the crashing:
TypeLoadException: Could not load type 'TwitterVisualizer' from assembly 'cf25c3822e3254345b872d6103147646, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'.
System.MonoCustomAttrs.GetCustomAttributesBase (ICustomAttributeProvider obj, System.Type attributeType)
System.MonoCustomAttrs.GetCustomAttributes (ICustomAttributeProvider obj, System.Type attributeType, Boolean inherit)
System.MonoType.GetCustomAttributes (System.Type attributeType, Boolean inherit)
UnityEngine.AttributeHelperEngine.CheckIsEditorScript (System.Type klass)
I’m getting this problem, this is how i came across this thread. when i open a project it throws a load of TypeLoadException error messages. It started after i received a GUI error when compiling xcode for an iphone project. I had had this problem before and had noticed that when you change certain settings for an iphone project that there may be a problem when compiling, restarting the project helped as it got rid of any inconsistencies ( read it some where on the forum ) but this time when reopening the project i got an army of typeloadexceptions and crash on scene play.
Its odd this topic was not responded to, i think we have the same problem its hard to say.
i’ll keep digging.
I’m having the same problem. My standalone project was working fine until today. I haven’t changed anything, it just show 2 similar errors mentioned above and when I start play Unity just crash.
Similar symptoms to gazbushell, except I am on a PC (which shares assets with macs via assetserver)
I think the TypeLoadExceptions errors were mainly fixed by doing a Reimport All to reimport all assets again.
I also fixed a few mac/pc line ending complaints, probably not relevant.
however now AssetServer is an inkle winkle bit confwused and thinks I have updated a gazillion files locally, mainly materials. 
(Just thought of one other thing: one of my monitors was changed last night and the errors started this morning. You would think this could not possibly be related but I have met a few bits of flaky behaviour in unity when the dual monitors being rearranged, for example dialogs showing corrupt video data, not even a menu bar, until I revert to a single monitor, which resets something. If a file load called some graphics routine, eg a progress indicator, which throws an exception… well its possible.)
I had the same problem this morning: “TypeLoadException: Could not load type …”, crashing Unity 3.1 on MacOSX whenever I tried to play a scene. This same project was working fine yesterday… 
Doing the following saved my project and my day: I copied the whole project directory to a new one, erased the Mono files at the root (the .sln, .pidb, .userprefs, .csproj files) and erased the builds. Then I opened the new project, and everything was OK… 
Reimporting the scripts folder fixed my problem but it reappears every now and then so I just reimport the scripts.
Yup just happened to me too! Really annoying as it was working half hour ago and I closed it and just reopened it and now it just crashes! I get the report request asking what I was doing, I just want to put “Minding my own business!” As I hadn’t changed or done anything! The only thing different was that I backed up using Time Machine in the interim, possibly made the Unity folder go screwy? I’ll give up today and try reimporting the scripts tomorrow I think.