Lately I have noticed everytime I loaded up a Wiktionary page (whatever the language) the logo wouldn’t appear at the top left.
I tried disabling Avast (for 10 minutes only! :)), refreshing the page and voilà! The logo appears.
I tried it with 3 or 4 different Wiktionaries (different languages).
I concluded that Avast is somehow blocking access to the images URL.
You can try with:
https://be.wiktionary.org/wiki/Першая_старонка
Don’t forget to clean the browser’s cache if you have visited the page before, or it will load the image from the cache.
André