What for http_404_webOC.htm?

Question

Skype

Greetings.
Two days ago, this began to appear in Skype:

And two such windows appear at once. Googling didn't turn up much. Tell me, please, what is it and how to win? Skype is fresh, antivirus too.
Thank you!

Answer 1

I asked myself - I answer myself.
A list has been created in the hosts file so that Skype does not show ads. After updating Skype, apparently, he stopped liking it and this window appeared.
PS Now one line in hosts is enough to not see ads:

127.0.0.2 apps.skype.com

Answer 2

Skype tries to give a preview of the site using a link in the conversation thread, the server responds with a custom 404 page without a file extension - Skype does not know how to open it and offers to save it as a file of an unknown type.