I can't edit my menu

Try deactivating your plugins. If that doesn’t fix it, see:

https://codex.www.ads-software.com/Forum_Welcome#Include_as_Much_Information_as_Possible

I have about 20 Plugins installed, how many should I deactivate?

I Deactivated lots of Plugins. Only 9 are active, but still there is same problem.

All of them if that’s what it takes – start one by one and see if the menu starts working – test after each one.

I deactivated all the Plugin, still there is same problem.

Okay, so leave them off and switch to Twenty Fifteen theme. BTW, do you have a LOT of menu items – like more than 70?

No, I have only a few pages, and not much items. Hardly 15 I think.

What is your site URL?

https://www.blenderskool.cf

Switch your theme to Twenty Fifteen.

Still the same problem, after doing that.

Try clearing your caching plugin –

<!– Dynamic page generated in 0.095 seconds. –>
<!– Cached page generated by WP-Super-Cache on 2015-04-21 18:32:29 –>

<!– super cache –>

I didn’t understand…

Go to Plugins, look under SuperCache settings and click on the setting to “clear” or “delete” the cache (not the entire plugin).

Did it, but still the same problem