Answers.Body: <p>The solution was to replace all references to <code>"reference":null</code> with  <code>"reference":""</code> in <code>/craft/vendor/composer/installed.json</code>.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-08-22T00:56:43.067Z
Answers.LastActivityDate: 2018-08-22T00:56:43.067Z
Answers.UserDisplayName: Tyssen
Body: <p>I'm attempting my first Craft plugin and trying to update <a href="https://github.com/matthewattanasio/Craft-Url-Decoder-Twig-Extension" rel="nofollow noreferrer">https://github.com/matthewattanasio/Craft-Url-Decoder-Twig-Extension</a> for Craft 3 and followed the instructions in the <a href="https://docs.craftcms.com/v3/extend/plugin-guide.html#loading-your-plugin-into-a-craft-project" rel="nofollow noreferrer">docs for loading plugins</a> which seemed to work in that the plugin appeared in the control panel, but I also got the following error:</p>
  
  <blockquote>
    <p>[UnexpectedValueException]
      Package cakephp/core's source key should be specified as {"type": ..., "url": ..., "reference": ...},
      {"type":"git","url":"https://github.com/cakephp/core.git","reference":null} given.</p>
  </blockquote>
  
  <p>and now when I try to run any more composer commands I get the same error so I'm unable to do</p>
  
  <pre><code>composer remove package/name
  composer require package/name
  </code></pre>
  
  <p>because I've made some changes to file names and need to update it.</p>
  
  <p>The plugin is still showing in the CP but showing old information and when I try to install it, I get a server error.</p>
  
Tags: <plugin-development><twigextension>
Title: UnexpectedValueException after loading plugin
ThreadText: # UnexpectedValueException after loading plugin
  
  (Asked by: username_0 on 2018-08-21)
  
  I'm attempting my first Craft plugin and trying to update <https://github.com/matthewattanasio/Craft-Url-Decoder-Twig-Extension> for Craft 3 and followed the instructions in the [docs for loading plugins](https://docs.craftcms.com/v3/extend/plugin-guide.html#loading-your-plugin-into-a-craft-project) which seemed to work in that the plugin appeared in the control panel, but I also got the following error:
  
  > [UnexpectedValueException]
  > Package cakephp/core's source key should be specified as {"type": ..., "url": ..., "reference": ...},
  > {"type":"git","url":"https://github.com/cakephp/core.git","reference":null} given.
  
  and now when I try to run any more composer commands I get the same error so I'm unable to do
  
  ```
  composer remove package/name
  composer require package/name
  
  ```
  
  because I've made some changes to file names and need to update it.
  
  The plugin is still showing in the CP but showing old information and when I try to install it, I get a server error.
  
  **Tags:** plugin-development, twigextension
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_0 on 2018-08-22. Score: 1
  
  The solution was to replace all references to `"reference":null` with `"reference":""` in `/craft/vendor/composer/installed.json`.
  
  
  ---
  
  