flags are disappered

Hi!

Could check your language switcher settings?
Do you use custom flags?
Could you provide a link to your website?

Hi,
Yes I checked the language switcher settings.
Yes I use the flags that plugin provided.

the page is https://koeri.boun.edu.tr

Let’s look for a conflict.
Could you try to de-activate all your plugins except Polylang?
If it still does not work, try switching to a different theme (Twenty Fifteen).

I cannot do that. the site is official web page.

I don’t know how to help…

Actually, I did not understand how but it solved in the afternoon.
Could you check now with your desktop?