<p>I had the same problem following that video, i assume the ReleaseCandidate upgrade differs from the beta upgrade. Following the instructions from the craftcms github repo worked for me. <a href="https://docs.craftcms.com/v3/upgrade.html" rel="nofollow noreferrer">https://docs.craftcms.com/v3/upgrade.html</a></p>

CC BY-SA 3.0
2018-01-10T20:56:05.467Z
Thanks Karl. That did the trick for me as well.
Jon Livingston
CC BY-SA 4.0
2018-07-23T01:03:21.177Z
instruction doesn't exist anymore
Nikolay Bronskiy
CC BY-SA 4.0
2018-07-24T13:44:52.703Z
Now that craft 3 is released you should use https://docs.craftcms.com/v3/upgrade.html to upgrade from v2 to v3.
karl
CC BY-SA 4.0
2018-01-09T20:17:11.317Z
2018-11-02T18:42:46.647Z
2018-11-02T18:42:46.647Z
karl
<p>I have installed composer successfully but when I try to add:</p>

<pre><code>composer require craftcms/plugin-installer
</code></pre>

<p>I get the following:</p>

<pre><code>Your requirements could not be resolved to an installable set of packages.

Problem 1
- craftcms/cms 3.0.0-RC4 requires craftcms/plugin-installer ~1.5.0 -&gt; satisfiable by craftcms/plugin-installer[1.5.0, 1.5.1, 1.5.2] but these conflict with your requirements or minimum-stability.
- craftcms/cms 3.0.0-RC4 requires craftcms/plugin-installer ~1.5.0 -&gt; satisfiable by craftcms/plugin-installer[1.5.0, 1.5.1, 1.5.2] but these conflict with your requirements or minimum-stability.
- craftcms/cms 3.0.0-RC4 requires craftcms/plugin-installer ~1.5.0 -&gt; satisfiable by craftcms/plugin-installer[1.5.0, 1.5.1, 1.5.2] but these conflict with your requirements or minimum-stability.
- Installation request for craftcms/cms 3.0.0-RC4 -&gt; satisfiable by craftcms/cms[3.0.0-RC4].

Installation failed, reverting ./composer.json to its original content.
</code></pre>

<p>I have also tried the following with no luck:</p>

<pre><code>composer require craftcms/plugin-installer --ignore-platform-regs
</code></pre>

<p>Note my composer.json file shows the following:</p>

<pre><code>{

"minimum-stability": "dev",
"repositories": [
    {
        "type": "composer",
        "url": "https://asset-packagist.org"
    }
],
"config": {
    "optimize-autoloader": true,
    "platform":{
        "php":"7.1.1"
    }
},
"require": {
    "craftcms/cms": "3.0.0-RC4"
}
}
</code></pre>

<p>Any help would be appreciated! On a side note this is a local install using Mamp Pro.</p>

CC BY-SA 3.0
2018-01-03T02:34:02.907Z
Is there a reason you're manually doing `composer require craftcms/plugin-installer`?  `craftcms/cms` requires it directly and https://github.com/craftcms/docs/blob/master/en/installation.md#2-create-a-new-craft-project pulls it in for you.
Brad Bell
CC BY-SA 3.0
2018-01-05T19:31:12.427Z
Something I unfortunately forgot to mention is that I'm upgrading from Craft 2 to Craft 3. I was following Mijingo's "Upgrade Craft 2 to 3" video and I can't get past the require craftcms/plugin-installer command.
Jon Livingston
<craft3><composer>
Composer conflict when installing craftcms/plugin-installer
# Composer conflict when installing craftcms/plugin-installer

(Asked by: username_0 on 2018-01-03)

I have installed composer successfully but when I try to add:
composer require craftcms/plugin-installer

I get the following:
Your requirements could not be resolved to an installable set of packages.

Problem 1
- craftcms/cms 3.0.0-RC4 requires craftcms/plugin-installer ~1.5.0 -> satisfiable by craftcms/plugin-installer[1.5.0, 1.5.1, 1.5.2] but these conflict with your requirements or minimum-stability.
- craftcms/cms 3.0.0-RC4 requires craftcms/plugin-installer ~1.5.0 -> satisfiable by craftcms/plugin-installer[1.5.0, 1.5.1, 1.5.2] but these conflict with your requirements or minimum-stability.
- craftcms/cms 3.0.0-RC4 requires craftcms/plugin-installer ~1.5.0 -> satisfiable by craftcms/plugin-installer[1.5.0, 1.5.1, 1.5.2] but these conflict with your requirements or minimum-stability.
- Installation request for craftcms/cms 3.0.0-RC4 -> satisfiable by craftcms/cms[3.0.0-RC4].

Installation failed, reverting ./composer.json to its original content.

I have also tried the following with no luck:
composer require craftcms/plugin-installer --ignore-platform-regs

Note my composer.json file shows the following:
{

"minimum-stability": "dev",
"repositories": [
    {
        "type": "composer",
        "url": "https://asset-packagist.org"
    }
],
"config": {
    "optimize-autoloader": true,
    "platform":{
        "php":"7.1.1"
    }
},
"require": {
    "craftcms/cms": "3.0.0-RC4"
}
}

Any help would be appreciated! On a side note this is a local install using Mamp Pro.

**Tags:** craft3, composer
> **Comments:**
> **username_1**: Is there a reason you're manually doing `composer require craftcms/plugin-installer`?  `craftcms/cms` requires it directly and https://github.com/craftcms/docs/blob/master/en/installation.md#2-create-a-new-craft-project pulls it in for you.  
> **username_0**: Something I unfortunately forgot to mention is that I'm upgrading from Craft 2 to Craft 3. I was following Mijingo's "Upgrade Craft 2 to 3" video and I can't get past the require craftcms/plugin-installer command.  

---

## 1 answers

### Answer by username_2 on 2018-01-09. Score: 2 | Accepted answer

I had the same problem following that video, i assume the ReleaseCandidate upgrade differs from the beta upgrade. Following the instructions from the craftcms github repo worked for me. <https://docs.craftcms.com/v3/upgrade.html>

> **Comments:**
> **username_0**: Thanks Karl. That did the trick for me as well.  
> **username_3**: instruction doesn't exist anymore  
> **username_2**: Now that craft 3 is released you should use https://docs.craftcms.com/v3/upgrade.html to upgrade from v2 to v3.  

---

