Can I regenerate the thumbnail or crops automatically?

This shouldn't be a common occurrence, however if you have a need for all thumbnails or crops to be regenerated with the default settings, you can do that (since v1.4).

You have two options:

• Remove the thumbnail files (located in a _thumbs directory below your gallery directory). The next time an image is loaded in the manager or front-end views, that will identify the file is missing and recreate it from default settings.
• Using a database management tool, edit the modx_moregallery_image table and empty the mgr_thumb value. That will cause a new image to be generated on the next request.

Please note that regenerating all thumbnails can take some time. With rather large galleries it might even time out the request. Just keep refreshing the list in the manager or frontend several times for a large gallery to be completely regenerated.

To regenerate crops to a default, you'll need to remove the relevant records in the modx_moregallery_image_crop table. They will then be regenerated according to the default configuration. Removing the crop files (also in the _thumbs directory) will also recreate the images, but with the same options as previously selected.