Website created in Web Presence Builder contains duplicated images in Image Gallery or Image Slider. It may lead to a script continuously running which makes the navigation really slow and make it impossible to save or publish the website.
This is a software issue #PPB-4356 , which has been fixed in Parallels Plesk 12.0.18 MU#29.
In case of Image gallery module the reason of such behavior is multiple entries with identical
uuid value which are pointing to the same image in
widget_imagegallery_local_images table of Presence Builder database.
In case of Image Slider module the reason is multiple entries with identical
image values in
Install MU#29 on the server.