Drupal: cannot redeclare date_api_views_data() error after installing Views 2.3

I had a lot of trouble trying to update the Views module. When I would attempt to run update.php, I got the White Screen of Death. I removed several modules and tried to view the modules page – and got this error:

cannot redeclare date_api_views_data()

Apparently back in one of the many updates, I had upgraded the Date module by dragging the new version on top of the old one. This must have left a conflicting file in place that only interfered once Views was updated.

The solution was to delete the Date module from the modules folder and install a clean copy from Drupal.org’s modules download site.

More on this issue:
View 2.3 fatal error