Route "easy_install.purge_configurations" does not exist

Can you please provide more info on it, I don't face this issue, provide the steps to reproduce if possible, I think you might be deleted the module source files without uninstalling it.

1. Attempted to install Easy Install on Drupal 8.7.3 in attempt to troubleshoot this error: "Unable to install Poll, core.entity_view_mode.poll.teaser, views.view.poll_admin, views.view.poll_list already exist in active configuration."
2. Install/enable failed. I CANNOT access Extend (admin/modules) menu, but I CAN access Extend/Intall menu. ???
3. Error Log as such:
>> Symfony\Component\Routing\Exception\RouteNotFoundException: Route "easy_install.purge_configurations" does not exist. in Drupal\Core\Routing\RouteProvider->getRouteByName() (line 201 of /home/ufvrclsrz1jy/public_html/core/lib/Drupal/Core/Routing/RouteProvider.php). <<

Ran into this issue when uninstalling this module which then broke the site.

I was able to restore the site by running `drush pmu easy_install` and then cleared (rebuild) cache with `drush cr` via command line.

I noticed that the route is defined by the following lines.

easy_install.purge_configurations:
 path: 'admin/modules/purge_configurations'
 defaults:
  _form: '\Drupal\easy_install\Form\PurgeConfigurationsForm'
  _title: 'Purge Configurations'
 requirements:
  _permission: 'administer modules'

The path should start with a slash, similarly to what done for the other route definition.

easy_install.purge_configurations_confirm:
  path: '/admin/modules/purge_configurations/confirm'
  defaults:
    _form: '\Drupal\easy_install\Form\PurgeConfigurationsConfirmForm'
    _title: 'Confirm Purge Configurations'
  requirements:
    _permission: 'administer modules'

I am not sure this change would stop the error from being shown, though, but the route definition should be corrected.

Fix looks good to me