Drupal 10.1.7 Upgrade Cannot redeclare Drupal\Core\Field\Entity\BaseFieldOverride::isInternal()

This code hasn't changed between 10.1.6 and 10.1.7 - please try re-installing with composer and checking any core patches you have applied.

Please also check if you have any patches applied for that file

We ran into the same exact error running updatedb after upgrading from 10.1.5 to 10.1.7. Deleted and reinstalled core and the problem was resolved.

For us this patch lead to the error message above:
https://www.drupal.org/project/drupal/issues/3274419 🐛 Make BaseFieldOverride inherit internal property from the base field Fixed
Since this is already in core we removed the patch and everything is working again.

Thanks