I've just updated the plug-in and was going to use it for the first time, but I'm unable to add a new gallery (error message "500 - Internal Server error - There is a problem with the resource you are looking for, and it cannot be displayed."). I tried using the "add slideshow" tool from within the page, and get the same message. I can add individual slides, but I haven't been able to go any further than that. I tried deactivating plugins one at a time to no avail. Any ideas?
https://wordpress.org/plugins/slideshow-jquery-image-gallery/