When updating Open Outreach, or when updating one or more of the modules shipped with Open Outreach, an error message appears: "Warning: class_exists() expects parameter 1 to be string, array given in the function _views_create_handler()"
This error appears to originate with the moving of a views handler from debut_media to file_entity whenwas committed. See . Since two handlers are registered with the same name, their data are appended to an array rather than a string.
To solve this error, first make sure that you don't have duplicate versions of the handlers. If you updated debut_media, ensure you delete the file debut_media/views/views_handler_field_file_rendered.inc. After doing so you will need to immediately flush your file registry. You can do so by flushing all caches. It's best to log into your site and be prepared to flush caches before you delete the file.
If the error persists, you may need to "revert" one or more features or views.
Before reverting, keep in mind that, if you have made customizations to the site, you can lose them by reverting.
Start with Views. If not already enabled, enable the Views UI module. Navigate to Structure > Views (admin/structure/views) and determine if any existing views show as overridden in database. For those views, consider reverting them. If you wish, you can first clone them so that you have a copy of a view with your customizations.
You can also use the Features interface to review and revert overrides. You may wish to install the Diff module, which allows you to individually review customizations made to components of features.
To revert: under Structure > Features, find the feature you want to revert. Under the State column, click the "Overridden" or "Needs review" link. This will show you a list of what's overridden and let you revert it. See the documentation here: http://drupal.org/node/582680.