Previous threads about that error message in Firefox. https://support.mozilla.org/en-US/questions/1032303#answer-656101 https://support.mozilla.org/en-US/questions/982298#answer-519224 https://support.mozilla.org/en-US/questions/1056108#answer-714562

Quick guess is a net filter like maybe Net Nanny.

at security.tls.insecure_fallback_hosts preferences I added www.onlinesbi.com, made it OK, started again firefox and checked but the the error is same i.e

"An error occurred during a connection to www.onlinesbi.com. SSL received a record with an incorrect Message Authentication Code. (Error code: ssl_error_bad_mac_read)

  * The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
  * Please contact the website owners to inform them of this problem.An error occurred during a connection to www.onlinesbi.com.

If that error comes in Firefox, Chrome, and Edge, the "problem" is external to the individual web browsers, like something in Windows 10 or installed in Windows 10.

Try to disable IPv6 (check for other possible causes as well).

• https://support.mozilla.org/kb/firefox-cant-load-websites-other-browsers-can