With NextGEN Gallery 2.0.27 you will encounter the following error when attempting to re-publish an existing image: Failed to move image ...
If you are tired of waiting for Photocrati to fix the issue with image republishing in NextGEN Gallery 2.0.x (to this day, the problem exists even in version 2.0.27), here is a solution. You would need to modify the xmlrpc.php script in the NextGEN Gallery's installation folder on your server, so be very careful.
Disclaimer: I will be not responsible for any damage caused by the following instructions in this post.
Here it goes...
The xmlrpc.php file you want to modify is located in <WORDPRESS ROOT FOLDER>/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/ngglegacy/lib/.
Save a copy of this file as xmlrpc.php.save, just in case something goes wrong and you need to roll back your changes.
Next, edit the xmlrpc.php script and replace the entire uploadImage function with the following code and save your changes. Now you should be able to repubilish your images.
Code fragment downloaded 108 times.
Keep in mind, if you install another NGG update, your changes to the xmlrpc.php file will be lost and unless this is finally fixed in the plugin's code, you would need to re-apply this remedy.