"Unable to parse YAML file" error

I sometimes get the error "Unable to parse YAML file: [could not find expected ':'] at line 2". Is there a way I can figure out what file is causing this error? Thanks!

 

I know it's used by text version of scenes, but we've got Asset Serialization Mode set to Mixed, and scenes are saving as .unity and .unity.meta files. It's a large project with lots of files... how would I locate the two files (it always appears twice when it does appear) that have the glitch? Clicking on the error message doesn't do anything. There's no indication anywhere what file actually contains the error. That's what I'm trying to figure out. If I could *find* the file causing the problem, I could probably fix the problem.

 

We are also seeing this issue. A lot.

We realise it's because YAML is used for scenes. But the error doesn't say what file it is unable to parse. That would be useful to know.

 

+1 for letting us know *which* file is causing the error.

 

Ya, the only solution I've found is to save everything and then reboot unity. I'm guessing it reformats the YAML files... but ya... preeeetty lame.

 

You should go thoug all of your .meta files and search for git or svn conflicts.
Here is small description and script in ruby to help you with that

 

Simply search for the occurrence of "<<<<" in your '.meta' files; it is caused by merging improperly in GIT as mentioned before.

 

[I know its an old thread and not specific to the Unity 5.0 Beta]
I do have this issue with Unity 5.0 RC2, everytime i open my project it gives me this error with no further explanation:
Unable to parse YAML file: [Control characters are not allowed] at line 0
The project is a little big to report a bug with the project, what can possibly cause this?

 

I have discovered since discovering this post that any syntax error in your yaml will cause this. It's just a generall error message stating something is wrong. Version control merge conflicts seem to be the most common way of getting this. As stated above, do a search for either "===" or "<<<<" within the yaml file. I also found that (after verifying the object and scene has been saved) deleting the yaml file experiencing the conflict will cause Unity to attempt to generate a new one, as if it was a newly generated asset. This newly generated asset won't have conflicts.

 

We had this just earlier, once each on a single Git pull, the first of the day on scenes. No idea why as our scenes are all binary (and still are, having checked). The only thing different to normal is we moved from 4.6.1f1 to 4.6.3f1 this morning.

 

A quick review of the logs, and it appears the errors were being spawned from mp3 files, not scenes.

Hasn't happened again, but at least I've something to bugette now.

 

I believe that regardless of how you have asset serialization there's still meta files generated that git will try to merge. It's normal behaviour is to ignore changes made to the same section of a file, leaving a conflict. I could be wrong but I suspect that may be what's happening?

 

That crossed my mind, though YAML is supposed to refer to scene files, not assets (if the editor log is anything to go by). Hasn't happened again anyway, and didn't do any damage that we can find. I dunno, Yesterday just didn't want to work. Even our Cloud Builds sat in a Restart loop for four hours until we switched from ILCPP to mono....life

 

This still happens on 4.6.6x

 

STILL HAPPENS >:[

 

Close Unity and from explorer search all .meta files and delete them. Now open the Unity. Works perfectly.

 

delete Library folder and open unity, it let unity remakes Library folder. and reopen unity, it fixed for my case.

 

Get it 100% of the time when creating a new blank Unity project in 5.3.3 and when I open previous projects. Deleting Library directory does nothing except waste precious time!

Does UT have an answer/suggestion?

PS. does seem harmless but who knows with Unity!

 

+1
This is happening all the time in Unity 5.3.4p1

 

+1
This is happening all the time in Unity 5.3.4p1 for me too, i have "force text" enabled

 

From what I can see (in my case) it is related to the opening splash screen when Unity launches. Not the projects themselves. As I get the same error with a brand new project with nothing in it. No scene files etc.

So I'm ignoring it...

 

Same: 5.3.5f1 here. Created blank project:

Code (CSharp):

1. Unable to parse YAML file: [Control characters are not allowed] at line 0

checked release notes of patched releases till 5.3.5p3. Non of them have a fix for now.

 

THIS ^^^

 

Just happened to me after a merge conflict using Git. The conflict turned out to be in ProjectSettings/ProjectVersion.txt

 

so, how did you fix it...? I tried to change the version number in the .txt file but I "didn't have permission" to save the changes

 

Still having this problem with 5.5.1p4 5.5.2p1 5.6.0b10

I removed the entire unity folder from my appdata. start unity, create new project. bam, yaml problem is there..

heres the logfile
(fun detail, editor is 5.5.2p1 while a bit further down unity says its 5.3.0

Code (csharp):

1.  
2. LICENSE SYSTEM [201738 13:21:55] Next license update check is after 2017-03-09T10:16:49
3.  
4. Built from '5.5/patch-release' branch; Version is '5.5.2p1 (9360c5517afe) revision 9658565'; Using compiler version '160040219'
5. OS: 'Windows 7 Service Pack 1 (6.1.7601) 64bit' Language: 'en' Physical Memory: 24575 MB
6. BatchMode: 0, IsHumanControllingUs: 1, StartBugReporterOnCrash: 1, Is64bit: 1, IsPro: 1
7. Initialize mono
8. Mono path[0] = 'C:/Program Files/Unity552p1/Editor/Data/Managed'
9. Mono path[1] = 'C:/Program Files/Unity552p1/Editor/Data/Mono/lib/mono/2.0'
10. Mono path[2] = 'C:/Program Files/Unity552p1/Editor/Data/UnityScript'
11. Mono config path = 'C:/Program Files/Unity552p1/Editor/Data/Mono/etc'
12. Using monoOptions --debugger-agent=transport=dt_socket,embedding=1,defer=y,address=0.0.0.0:56612
13. ListPackages failed, output: {
14.   "name": "unity-editor",
15.   "version": "5.3.0",
16.   "problems": [
17.     "invalid: unity-editor-home@0.6.17 C:\\Users\\MY_USER_NAME\\AppData\\Roaming\\Unity\\Packages\\node_modules\\unity-editor-home",
18.     "invalid: unityeditor-collab-history@0.6.10 C:\\Users\\MY_USER_NAME\\AppData\\Roaming\\Unity\\Packages\\node_modules\\unityeditor-collab-history",
19.     "invalid: unityeditor-collab-toolbar@0.6.15 C:\\Users\\MY_USER_NAME\\AppData\\Roaming\\Unity\\Packages\\node_modules\\unityeditor-collab-toolbar"
20.   ],
21.   "dependencies": {
22.     "unity-editor-home": {
23.       "version": "0.6.17",
24.       "from": "unity-editor-home.0.6.17.tgz",
25.       "resolved": "file:unity-editor-home.0.6.17.tgz",
26.       "invalid": true,
27.       "problems": [
28.         "invalid: unity-editor-home@0.6.17 C:\\Users\\MY_USER_NAME\\AppData\\Roaming\\Unity\\Packages\\node_modules\\unity-editor-home"
29.       ]
30.     },
31.     "unityeditor-collab-history": {
32.       "version": "0.6.10",
33.       "from": "unityeditor-collab-history.0.6.10.tgz",
34.       "resolved": "file:unityeditor-collab-history.0.6.10.tgz",
35.       "invalid": true,
36.       "problems": [
37.         "invalid: unityeditor-collab-history@0.6.10 C:\\Users\\MY_USER_NAME\\AppData\\Roaming\\Unity\\Packages\\node_modules\\unityeditor-collab-history"
38.       ]
39.     },
40.     "unityeditor-collab-toolbar": {
41.       "version": "0.6.15",
42.       "from": "unityeditor-collab-toolbar.0.6.15.tgz",
43.       "resolved": "file:unityeditor-collab-toolbar.0.6.15.tgz",
44.       "invalid": true,
45.       "problems": [
46.         "invalid: unityeditor-collab-toolbar@0.6.15 C:\\Users\\MY_USER_NAME\\AppData\\Roaming\\Unity\\Packages\\node_modules\\unityeditor-collab-toolbar"
47.       ]
48.     },
49.     "unityeditor-cloud-hub": {
50.       "version": "0.0.15",
51.       "from": "unityeditor-cloud-hub-0.0.15.tgz",
52.       "resolved": "file:unityeditor-cloud-hub-0.0.15.tgz"
53.     }
54.   }
55. }
56.  
57. Unable to parse YAML file: [mapping values are not allowed in this context] at line 1
58.  
59.  
60. (Filename: C:\buildslave\unity\build\Runtime/Serialize/TransferFunctions/YAMLRead.cpp Line: 180)
61.  
62. Unable to parse YAML file: [mapping values are not allowed in this context] at line 1
63.  
64.  
65. (Filename: C:\buildslave\unity\build\Runtime/Serialize/TransferFunctions/YAMLRead.cpp Line: 180)
66.  
67. IsTimeToCheckForNewEditor: Update time 1488978151 current 1488975872
68. Unable to parse YAML file: [mapping values are not allowed in this context] at line 1
69.  
70.  
71. (Filename: C:\buildslave\unity\build\Runtime/Serialize/TransferFunctions/YAMLRead.cpp Line: 180)
72.  
73.  

 

In my case the problem NUL control characters at the end of meta files of two materials which was reserialized after upgrading from Unity 5.5.1f1 to Unity 5.6.3.

 

2017.2.1 and it still happens, and I'm talking an new empty project. Right? No assets, no Git. Create empty new project, see errors.

 

2017.3.1f1 I got this problem

 

Same. Maybe file a bugreport?

 

Four years later and still not addressed? I guess Unity expects us to just ignore it though I do not find that an acceptable solution.

 

I get this error even when I create a brand new project from scratch. On whichever version of Unity, just happened on a fresh install of Unity 2018.2 beta on a brand new project. Twice, as always, except apparently now they let us know which file causes the problem, in my case: ProjectSettings/ProjectVersion.txt. Opening the file however gives me no indication of any problems, as it has this single line:
m_EditorVersion: 2018.2.0b1

 

Same thing here, Unity 2018.1.b13

 

Still happen on 2017.4.0f1, I created a brand new project, then I got this error.

 

Still in 2018.1.5

 

You really have to find all mege conflicts in everey .meta file and in every .txt file in ALL your projects. Even if the project has nothing to do with your current project.

 

Elaborate. Meta files and library data is not shared between projects.

 

Not saying you're wrong... But that makes no sense to me. If that is in fact true, I'd rather just press "Clear" every time I open Unity instead of scouring through all my projects.

 

It is not true.

 

I don't know how Unity handles Meta files between different projects, but I had this error in all my projects including newly created ones.

I used the "find in files" function in Notepad++ to search in all .meta files in my "Unity Projects" folder which showd me merge conflicts in 1 of my 14 projects. (I simply searched for "<<<<<<"). I fixed all merge conflicts I found and voila! No annoying yaml errors appered ever again.

So it's definitely true, at least in my case.

 

Oh it's an old friend.Let's clear it ahhhh..

 

Unity really does not handle meta files between projects and it is not really supposed to touch files outside the project you are opening either. If it does in any way, that is a serious bug, you should reproduce and report it, as something is very not right. You can check what files it opens on launch with http://www.nirsoft.net/utils/process_activity_view.html, if you see anything unexpected then report the bug. I did attempt to myself, even injected the usual <<<<<< in various assets and meta files across multiple test projects and it did not access any of them.

The only files it does open across "all" projects are ProjectSettings.asset and ProjectVersion.txt files for every project that is in the recently opened projects, when the select project dialog opens on launch. That will cause those errors if there are merge conflicts in any of those files, but none of the other ones that I could find.

It's not that I don't believe what you are saying, I just think that the workaround you are applying is masking what is really occurring and that you should investigate more fully and report it to Unity.

 

[RESOLVED] Because this is the top search on Google, confirming fix for this.

This was caused in our project due to an unresolved merge conflict in ProjectSettings\ProjectVersion.txt.
(ie <<<<<<<)

Remove merge conflict lines and problem resolves.

If you have a merge conflict in ANY ProjectVersion.txt in your recently opened projects the error will appear. Check this file in your other projects and fix as above to remove error across all.

What is likely happening is the error is happening in the "Projects" pop up when you first open unity, but then doesn't display until you select and open a project.

 

Cool, cheers for getting to the bottom of this! I have an aversion towards solutions that make no sense and moving on without getting to the true cause of problems, as it usually results in problems down the line.

 

For me this happened because the project had meta files whose contents are all just repeated null characters inside. Supposedly this happens if you get a power failure/cutoff while a file is open, and I do have a teammate whose old laptop keeps turning off on its own, and he inadvertently added those files to the repository. I suppose the best thing to do in such cases is to delete those affected meta files and let Unity recreate them, if no backup can be retrieved from version control.