SlaviO

Ok, I has understood the problem instead of a list of pictures and slideshows issued 404 error: in options (/wp-admin/options-permalink.php) my site was “/%postname%.php”, changed it to “/%postname%” and it worked!!!

When I click “start slideshow” сontent get an error 404 page with an address of gallery in the address bar.

Fix not worked for me 🙁
All the same content in an error 404 page with an address of gallery in the address bar.