After you have activated the access codes in your album, deleting all images associated with a code will remove it completely from the album. This is to prevent many empty codes from cluttering the album contents.
If you've tried adding a code and editing it to bring back the previously removed one, you may have encountered the following error:
"Error! Cannot use same password twice."
The system does not allow you to duplicate access codes, and even though it has been removed from the album, the code still exists in the system's data.
To properly add the access code back in, you'll need to do the following:
1. Inside the album, click "Individuals actions" followed by "Add person (new access code)
2. For the newly created, random access code, click "Access codes actions" followed by "Upload more photos..."
3. Upload the photos that will be associated with the access code you want to bring back.
4. After the images are generated, click on the first image and then on the preview that pops up on the right, or on "Add access code" underneath the image. Change the access code from the randomly generated one to the code you want to bring back.
5. Don't forget to click Save!
After you have clicked Save, the access code should appear again like normal. If you need to add more codes that were removed, simply follow the above instructions again. If dealing with multiple codes, it may be easier and faster to deactivate the codes and then reactivate them once all the photos have been uploaded again.