# Troubleshooting

# Sync the database schema

In rare situations, the WordPress database schema might not match the schema expected by the applications or plugin. For example switching to multisite, and the wp\_users table is missing the spam and deleted colums

To fix this issue locally, **create a file in the *mu-plugins*** folder such as `mu-plugins/db-upgrade.php` with the following contents, and load the site:

```PHP
<?php
require_once ABSPATH . 'wp-admin/includes/schema.php';
require_once ABSPATH . 'wp-admin/includes/upgrade.php';
dbDelta( wp_get_db_schema( 'global' ) );
```

After the page is loaded the file can be deleted.

# Troubleshooting local environment problems

*A collection of troubleshooting tips to diagnose issues with a local environment that's not working right.*

### WP CLI Issues

1. Try `wp cli info`, if this fails then the issue is limited to WP CLI or PHP as this doesn't touch the codebase / DB.

# Resolving composer.lock merge conflicts

`composer update --lock` fixes lock file when merging branches with .lock conflicts.

# Package type "library" is not supported

You might see the following message after running composer:

```
Reading /Users/svandragt/.composer/auth.json
Reading /Users/svandragt/dev/_hm/siemens/milestones.local/vendor/composer/installed.json
Reading /Users/svandragt/.composer/vendor/composer/installed.json
Loading plugin OomphInc\ComposerInstallersExtender\Plugin_composer_tmp1
Package type "library" is not supported
```

This is a [bug in oomphinc/composer-installers-extender &gt;1.1.2 &lt;= 2.0](https://github.com/oomphinc/composer-installers-extender/issues/26) and can be fixed by downgrading to 1.1.2

```shell
# Pin version to 1.1.2
composer require oomphinc/composer-installers-extender 1.1.2 --no-update --no-plugins
# Update the plugin
composer update oomphinc/composer-installers-extender --no-plugins
# Update dependencies
composer update oomphinc/composer-installers-extender
```