Server self connect: Not expected HTTP response: 401

Hello,

i installed Backwpup but get the information:

Server self connect: Not expected HTTP response: 401
Date: Tue, 07 Feb 2017 08:49:27 GMT
Content-type: text/html; charset=utf-8
Server: Apache
Www-authenticate: 
Vary: accept-language,accept-charset
Accept-ranges: bytes
Content-language: en
Expires: Tue, 07 Feb 2017 08:49:27 GMT

...

 <h1>Authentication required!</h1> <p> This server could not verify that you are authorized to access the URL "/wp-cron.php". You either supplied the wrong credentials (e.g., bad password), or your browser doesn't understand how to supply the credentials required.

…

I tried to enter my password under “network” but this doen´t help. I am new to wordpress and it´s probably a very simple problem, but I don´t know how to solve it. I am grateful for any help.