Program and signatures are not updated

When trying to update the program or signatures, there is an endless search for an update.
255af789343d03d1c2c13f27881f4932

Also the second question:
When I try to visit Avast.com or Avast.ua, I get an access denied message.

Maybe your IP or ISP is (wrongly) banned because of the sanction to Russia. Try rebooting your router, it may change your IP address.