Fatal Error: type == kMetaAssetType pathName.find("library/metadata") != 0

Hi,

I am trying to downgrade a Unity 4 project back to Unity 3.5.

I do have a backup, so this is what I have done so far, but I am still getting this error when loading Unity 3.5

1. Uninstalled Unity, including registry keys and some other leftover files in Documents and Settings (Windows XP)
2. Reverted my project back to its original state (pre Unity 4)
3. Since it is a .meta source controlled project, I deleted the Library folder.

So as far as I understand, this is like I never had Unity 4 in the first place. But still, something in my system remembers it and shows this incompatibility error.

Can anyone help?
Is there anything else I need to remove from my system to remove all trace of Unity 4?

 

Thanks.
The only thing they say there is to rename the bootcamp project.
I do not find it anywhere on my computer (where should it be located?).

I only found three versions of Angry Bots, and deleted them, but still when loading my project I get an error.

 

Thanks - I did just that. In fact, just to be sure, I uninstalled and in the registry editor, I deleted almost everything that had Unity in it.

Then after reinstalling, I was able to get a clean installation completely - it asked me for my license again and all.
So now I am back in business, and manually rebuilding everything I lost in that upgrade.

I think there is one thing for Unity to get from all this - is to build a more symmetric uninstaller.
At Uninstall, there should be a checkbox or two asking if I want EVERYTHING removed (including all those pesky registry entries) or not.

Sort of like when you uninstall an iOS game, it asks you if you want to keep the Game Center data.

 

Hi, I am having the same problem.

Fatal Error ! type == kMetaAssetType pathName.find ("library/metadata") != 0

I'm trying to go back to Unity3.5 ( I have Unity4 iOs Pro )
I also removed all files etc.. and emptied bin + re-start.

Then I install Unity3.5 but I get the error ???????

ANy ideas ??

 

I did rollback from version 4.0 to 3.5.6, I got the same problem, all I did was just removing manually the folder C:\Users\Public\Documents\Unity Projects\4-0_AngryBots, that's all... my version 3.5.6 now works fine. I hope it helps.

 

Deleting Angry Bots worked for me as well. Thank you all!

 

If you are using external version control, this can be caused by using *.meta files generated by Unity 4 in a Unity 3.5 project. In your file browser, just search the project for *.meta and delete all the meta files (Disclaimer: you may want to make a backup first!). Unity will automatically regenerate all the meta files for 3.5 on startup and the crash should go away.

 

alejogn, thanks for the heads up, indeed removing the 4.0 version of Angry Bots worked like a charm

 

you are true............

 

hi folks - i'm on a Mac, trying to do what DannyB did and downgrade a project built in Unity 4.1 inside 3.5.7. i backed up my project and on the copy i deleted the Library folder contents and the ProjectSettings.asset file and went right into opening the scene in Unity 3.5.7( by right clicking and open in Unity 3.5.7). it imports for a while but halfway through i get the same error as everyone else did. i have removed Angry Bots 4.0 folder, but no change in behavior.

Is there anything more i need to do to consider myself ready? should i also wipe the ProjectSettings folder for the project in question? Ideally, I would like to keep both versions of Unity running on this machine if possible but if there's interference caused by Unity 4.1 being there i'd like to know.

any advice or links appreciated.

best,
scott

 

Hey metaphysicia - funny you mention it now, I just recently (a few days ago) found the courage to retry that upgrade from Unity 3.5.7 to the 4.x branch, and although it also took me several days with crashes on the iOS device (caused by a bug in Unity 4.2), I can say that I am now past it, and running Unity 4.2.1 with my project and everything seems stable. Touch wood.

Now, I am assuming that you have at least one stable copy of your project, that was never opened in Unity 4 (only opened in 3.5.x). Correct?
If so, then your situation is good. Keep this folder safe and backed up on 5 different backup sites...

Now, I would recommend setting up your machine so you have two versions running in parallel. Here is the official guide for running two versions. Followed it to the letter, and I am now running two versions on both my PC and Mac.

Finally, once this is done, you can copy your 3.5 project to another folder, intended to be opened and migrated in Unity 4.
Do not copy the entire folder as is, I recommend following my answer to this Unity Answers question.

Also, if you are trying to install anything prior to Unity 4.2.1, I recommend against. 4.2.1 fixed some important bugs.

If you do not have a stable 3.5.x copy of your project, thats a different story...

 

yeah - i'm afraid i'm in that latter boat. briefly explained, i was contracted to provide some simple interactive examples in Unity, and the dev never told me what version they were using. so i went ahead and built it in Unity 4.1 (i have 4.1.2 currently working). come to find a bit down the path that they're actually on Unity 3.5.7 and refuse to upgrade to Unity 4. if i were a more experienced coder/developer i would have likely asked well in advance. i find 4.1.2 to be relatively stable for my purposes.

anyway, i'm basically stuck at that message at the moment, and trying to avoid starting again completely from scratch. i was told from someone else that to downgrade your project you needed to remove the Library folder the Temp folder (if existing) and the .asset file stating the project version. i still have the ProjectSettings folder that might be interfering.

i do have a backup of the 4.1.2 version of the whole project, so at least all the assets are safe, but no 3.5 version of the project ever existed. i'll keep hunting around but if you or anyone else have any tips, it'd be appreciated. checking the information of running two versions i can say with certainty that i'm doing everything correctly. each Unity folder has a unique name under /Applications and i did not rename any of the subordinate items. as mentioned earlier i also removed the 4.0 version of AngryBots.

anyway whatever advice can be offered would be much appreciated. thanks!

scott

 

As far as I know, downgrading a project is not possible. If you delete the Library folder, you will lose all the connections unless you have meta files enabled, and in this case, Unity will try to rebuild your Library folder, and likely fail, since the meta files are incompatible...

I dont know how much of your work is code, and how much is complex prefabs, unless you have many prefabs, or very complex assets, you should consider rebuilding. I would be surprised if there is a way to downgrade.

This error in the initial post of this thread is all about the incompatibility of the meta data. The meta data is responsible for all the connections...

 

here is solution which worked for me!

I got this error when I was trying to import (probably) unity 4 package from other developer

1. download the ProcMon
2. add unity.exe as filter, press add hit ok



3. run unity and when you get error switch to procmon and find the lines with "Editor.log"



4. scroll up (before "Editor.log" lines) you will find the file and its path which causing that error !

in my case the metadata file was this one:

rename it and you will save almost whole project
this helped me and I hope will help you too

 

after uninstall and trying every thing else mentioned deleted entire meta folder and did the trick...THANKS

 

I get the same issue when I try to import unity 4 package into unity 3.5, it crash!!!!!!. however everytime we open unity3d, will open the last project automatically. To solved this problem, just change the file path of last openned project, e.g rename the .unity file.which make unity3d to open another project.

 

Or press the Alt key when you launch Unity, which will cause the project wizard to open, instead of opening the last project.

Or or choose the "Always Show Project Wizard" option from the Editor Preferences.

 

If the problem is not in Angry Bots demo and is it your own project , try to:

1) Start Unity editor and create a new empty project
2) Open the concrete scene in your another "not working" project [Ctrl + O]
- the editor ask you if you want to open corresponding project [confirm]

Note: you can also delete the cache and metadata before, but it will cause some asset import settings changes, etc. (backup and try it).

It Worked for Me today

 

All I needed to do, was to open the unity file for Angry Bots (AngryBots.unity), open a new blank project in Unity, and finaly close Unity.

It should work now. It did for me, at least.

File location for AngryBots.unity:
C:\Users\Public\Documents\Unity Projects\3-5_AngryBots\Assets

 

I'm having the same problem now when I try to import my Unity 4 project in Unity 3. I want to sell my asset in the Asset Store and I'd like the system requirements to be Unity 3 instead of Unity 4, since the code works just fine in Unity 3.

I use a completely new pristine Unity 3 project and once I import my package it crashes. I can get it to work again by deleting the metadata in the Library folder of the Unity 3 project, but that messes up all my included example scenes, they become unusable. Is there any other solution?

 

I wrote a solution a few post above !
http://forum.unity3d.com/threads/fa...-find-library-metadata-0.160690/#post-1376458

 

Yes, a solution on Windows I'm on OS X.