Why can't I access some sites via https?

Question

Digital certificates

The essence of the problem is that I can’t access some sites, for example -
https://www.learnjavaonline.org/
https://www.learnpython.org/
https://zakupki.gov.ru/

However, the link without https will work - www .learnjavaonline.org will open fine.

Opera swears like this -

This site cannot provide a secure connection
The www.learnjavaonline.org site sent an invalid response.

Chrome -

This site cannot provide a secure connection
The www.learnjavaonline.org site sent an invalid response.
ERR_SSL_PROTOCOL_ERROR

muff-

Error establishing secure connection
An error occurred while connecting to www.learnpython.org. SSL received a record that is longer than the maximum allowed. Error code: SSL_ERROR_RX_RECORD_TOO_LONG
The page you are trying to view cannot be displayed because the validity of the received data cannot be verified.
Please contact the website owners and inform them of this issue.

Donkey -

Enable TLS 1.0, TLS 1.1, and TLS 1.2 in advanced settings and try connecting to https://www.learnjavaonline.org again . If the error persists, this site may be using an unsupported protocol or cipher suite, such as RC4 (link to info article), that is not considered secure. Contact the site administrator.

The problem is on all devices connected to the network, i.e. on phone and tablet too.

I checked the time, tried ipconfig / flushdns, set dns from google / yandex, for the sake of interest I reinstalled Windows on my PC. During the existence of this problem, I managed to change the router, now I have MI-3 with firmware from Padavan, before that I had Asus RT-N12.

What could be the problem? Is it time to call the provider?

Answer 1

In general, the solution to the problem is quite simple - it was necessary to enable SSL2, SSL3 in the browser properties

Answer 2

1 and 2 opened without problems - Win10, Mozilla
3 - there was some kind of trouble at work with certificates for viewing public procurement tenders.

Answer 3

1 and 2 opened without problems. The purchasing site says that they use outdated technology - they probably don't have SSLv3 disabled ;)