Flutter Pub: Expected a key while parsing a block mapping. path:

Android Problem Overview

I'm using JSON file and register in Pubspec.ymal but showing error and also when I use an image and register it, the same error also occurs. Maybe there is a formatting mistake in it, but don't know what the problem is.this is the doc I followed.

> Error on line 29, column 5 of pubspec.yaml: Expected a key while parsing a block mapping. > assets: > ^

This is my pubspec.yaml file

name: jsondata description: A new Flutter application.
  
  dependencies:  
 
  flutter:
 
  sdk: flutter
 
  cupertino_icons: ^0.1.0
  
  dev_dependencies:   
 
 flutter_test:

      sdk: flutter
  
    flutter:
 
    uses-material-design: true
 
      assets:
  
       - loadjson/person.json

Android Solutions

Solution 1 - Android

Spaces are significant in YAML

assets is indented too far

flutter_test:
  sdk: flutter

flutter:
  uses-material-design: true
  assets:
    - loadjson/person.json

Solution 2 - Android

It is because of the indentation of your code.The uses-material-design should be on the same line vertically as the assets:.

 uses-material-design: true
  
 assets:
   - images/picture.png

Solution 3 - Android

> Error on line 29, column 4: Expected a key while parsing a block > mapping. assets: > > flutter: uses-material-design: true assets: > - assets/images/image.jpg

In my case i just added # in front of uses-material-design: true

Try below code

flutter:   

  # uses-material-design: true 

   assets: 
    - assets/images/image.jpg

its working fine.

Solution 4 - Android

In my case, uses-material-design indentation was broken. I put 1 (one) more space before it, and it worked fine.

Solution 5 - Android

With removed comments, original, generated by default pubspec.yaml looks like this

flutter:
  uses-material-design: true
   assets:
    - images/abc.jpg

But it isn't vaild. It doesn't works. It should be:

flutter:
  uses-material-design: true
  assets:
    - images/abc.jpg

Important: Spaces are significant in YAML

Solution 6 - Android

Spaces are very important in .yaml file.

Just make sure your code is on the same line (vertically) according to key and value.

If you are still confused please watch this simple video. It'll help you to solve the issue easily. > https://imgur.com/gallery/ngoXwUe

Solution 7 - Android

**Error on line 46, column 4: Expected a key while parsing a block mapping. assets:

flutter: uses-material-design: true assets: - assets/dhaka.jpg**

Make sure when you uncomment the line please check indentation. if indentation is wrong it's going error. flowing this image. Happy coding !!!

Solution 8 - Android

You have to be careful with space in yml file

Solution 9 - Android

If images folder is next to lib folder, you need a ./, because it is not on the same level as the pubspec.yaml, then, in pubspec.yaml uncomment:

assets:
- ./images/   //Watch for spaces and indentation!!

Now you can use them:

Image.asset(
          '../images/nature.png',
          width: 600,
          height: 240,
          fit: BoxFit.cover,
        ),

Solution 10 - Android

Get same problem after uncommenting assets and image link sample in pubspec.yaml.

If you faced problem with assets, like I was. Make sure that it starts with same column(starts with same indent as pre-defined property like uses-material-design). After uncommenting in my case, their location was different.

After that, the problem was solved.

Solution 11 - Android

In My Case, the image was too large to load, decreasing dimension of image worked.

Solution 12 - Android

Please make sure that we don't have unwanted whitespace since yaml structure is sensitively considering the white spaces. Please refer the documentation for more info as below link,
https://docs.ansible.com/ansible/latest/reference_appendices/YAMLSyntax.html

Solution 13 - Android

As @Baftek mentioned , just indent before uses-material-design:true and press Ctrl+Alt+l (Intellij or Android Studio) to reformat file.

Solution 14 - Android

Issue is related with indent spacing, check your spacing, it should work fine
fonts: - family: CM Sans Serif fonts: - asset: assets/fonts/cm_sans_serif_2012.ttf

Solution 15 - Android

Assets should be on the same line as uses-material-design:

  uses-material-design: true
  assets:
    - images/myimage.jpg

Indentation Rules for pubspec.yaml

uses-material-design = 2 spaces
assets = 2 spaces
-images/ = 4 spaces
fonts: = 2 spaces
- -family: = 4 spaces
- fonts: = 6 spaces
- -asset: = 8 spaces

Content Type	Original Author	Original Content on Stackoverflow
Question	Farhana Naaz Ansari	View Question on Stackoverflow
Solution 1 - Android	Günter Zöchbauer	View Answer on Stackoverflow
Solution 2 - Android	EngineerDanny	View Answer on Stackoverflow
Solution 3 - Android	Manikanta chadaram	View Answer on Stackoverflow
Solution 4 - Android	Bartek Pacia	View Answer on Stackoverflow
Solution 5 - Android	Mahendra Sri Dayarathna	View Answer on Stackoverflow
Solution 6 - Android	Haseeb Nazir	View Answer on Stackoverflow
Solution 7 - Android	amirul	View Answer on Stackoverflow
Solution 8 - Android	Achraf Farouky	View Answer on Stackoverflow
Solution 9 - Android	TiyebM	View Answer on Stackoverflow
Solution 10 - Android	Vergo	View Answer on Stackoverflow
Solution 11 - Android	DevChamp	View Answer on Stackoverflow
Solution 12 - Android	Deva	View Answer on Stackoverflow
Solution 13 - Android	Sumit Shukla	View Answer on Stackoverflow
Solution 14 - Android	msk_sureshkumar	View Answer on Stackoverflow
Solution 15 - Android	Sharon	View Answer on Stackoverflow