All good. My issue was resolved. Thank you very much.
Unfortunately I did not pay attention to that which was the original version.
I can note that I’ve updated the plugin before updating WP to version 4.0
Gallery is located at: http://oaza.lviv.ua/galereia/
Error message appears after creating a new album.
See – https://dl.dropboxusercontent.com/u/23128142/tmp/wp4.JPG
Here are some screenshots:
https://dl.dropboxusercontent.com/u/23128142/tmp/WP1.JPG – Overview
https://dl.dropboxusercontent.com/u/23128142/tmp/WP2.JPG – Albums
https://dl.dropboxusercontent.com/u/23128142/tmp/wp3.JPG – Galleries (See number of galleries on the right)