Known issue, being discussed here: https://www.drupal.org/project/drupal/issues/3567483
Discussion
Loading...
There does seem to be an issue with the new "main" Drupal core branch introduced today:
It throws an UnexpectedValueException in Composer's VersionParser, called by Core's getPossibleCoreUpdateVersions()...
Known issue, being discussed here: https://www.drupal.org/project/drupal/issues/3567483
If your #Drupal 8/9/10 site is crashing on /admin/ pages due to the new "main" branching scheme in D11, a simple drush cache rebuild won't be enough.
This will do the trick:
```
drush php:eval "Drupal::service('update.manager')->refreshUpdateData()"
```