Hi,
I am sorry this happened to you! We tested the plugin on several sites and different versions of php and wordpress. It is possible that our plugin conflicts with one of your plugins, this is not possible for most users.
Most likely this is a php error, you could enable php errors according to this instruction:
https://digwp.com/2009/07/monitor-php-errors-wordpress/
Send me the error text so that I can fix the problem. Then go back to disable php errors.
Best regards, Alex
I can’t afford to update the plugin again to look for those errors.
I’m literally re-uploading hundreds of nextgen galleries because I wasn’t able to successfully restore everything because of the file size of these images.
I’ll wait until this update matures.