Error in Unity after opening 4.3 file in 4.2.1

So I downloaded Unity 4.3 for my school projects. But my school iss still using 4.2.1. So for one assignment I was using 4.3. But after finding out which version my school is currently using I switched to 4.2.1 but opened the 4.3 in 4.2.1. I didn’t get any data loss but now I’m getting an script error like this:

typeTree.m_Children.front ().m_Type != SerializeTraits::GetTypeString (Null)

I am only developing a level and not planning on scripting at all. But this error keeps getting to me and I don’t want my programmer to deal with the hassle. I can still click on play and move around in my level, but the error still persists. I would appreciate help if anyone can.

You cannot open a Unity 4.3 project in Unity 4.2.x. If it kinda works, then that it lucky, since it’s not meant to work.

Is there any way to fix this?/What does this mean? I have the same problem and I’ve had no choice but to roll back to 4.2.2f1 because of the terrible Windows performance in 4.3.

Same issue here: tries 4.3, performance sucks, rolling back, can’t… kinda trapped here.

Glad to know that I’m not the only one with this issue. To Graham, since everything works aside from the error I stated above. Should I start from scratch with a new unity 4.2.1 project or keep the one I have and hope for the best?

Revert to your pre-upgrade backup. If you did not take a backup of your 4.2.2 project, then I’d advise you to re-create it rather than hope the error you get doesn’t cause you any problems. (What would be awful is if you carried on, and the day you plan to make your final build something else goes wrong. Biting the bullet now is a better approach, I think. Not one that’s pleasant, of course.)

It was really unhappy act for me to upgrade to v4.3.1. It was a big mistake. My android application become unusable on some devices after that. Unfortunately, it was known after the publication the application at the Google Play when thousands of customers downloaded it and some of them became to claim. So I had to revert to the Unity v4.2.2 and rebuild the project.

I could not to revert from back-up because I have made some changes in different places of the project and scenes after upgrading Unity.

I was able to remove the “typeTree.m_Children.front ()…” error by some magic manipulations like deletion the Library folder and some files and deletion some other files, reimporting assets etc.

Now its working. Since now, I will think 10 times before the upgrading… It’s really dangerous.

Ran into the same issue. Tried creating a new project and copying over my assets, but the issue persisted. Turns out it is related to loading prefabs. It looks like adding the prefab to the scene and hitting apply fixes it up. I’m gonna try writing an editor script to touch all my prefabs in this way.

I got that editor script working, but it looks like it’s more than just prefabs. Getting the same error for materials and models now too. Was getting it for scenes, but opening and resaving them worked to fix them.

One of the magic thing I made to make my project work is switching asset serialization mode couple of time (force binary, force text). And reimport all of them.

This worked for me as well. It’s very odd that I had this issue in the first place, as I can’t imagine how I would have imported assets from a newer version of Unity into that project.

What would be really freaking great is if there was some indication of which asset was causing the issue. Having to revert hundreds of assets is a time consuming and frustrating task, made worse by the idea that somewhere in the chain of code that spit out that error, there must surely have been some way to specify the source of the problem.

Had to roll back to 4.2.2 because of the black screens on Android issue. I just removed everything other than the Assets folder and then went through re-setting all of the play/quality etc. settings.

Thanks! Switching to binary, text, and back to mixed cleared up all but 8 of them that show when I open the project. Reimport didn’t help at all.

helped here too. thanks

probably you are using some mouse events with android build (to emulate touch in the easy way). putting a small image (32*32) for the mouse icon in the build settings, will stop showing the blue/black screen !
That’s at least what happened in my case.