Cannot save options

Hi,
At first after installing the plugin I know that I could change the options, changed a few things, displayed texts to polish, but wanted to go back to fancybox and something broke (save stopped working) so I tried reseting the options. Now I cannot change anything and the options stayed as they were after the reset.

Need assistance.

Tried turning the plugin on and off again. Did not help.

Nothing in the console.

Best regards,
Anna

https://ww.wp.xz.cn/plugins/nextgen-gallery/