Go to about:preferences#privacy and then scroll down to "Notifications" and click "Permissions" and delete the entry that is being blocked.

Thank you for the solution. But, I could not find the name of the website in the list. This website is www.mediafire.com. It is not in the list. However, when I am trying to browse the site, it is giving this message: "This webpage has been blocked". Thanks in advance for further assistance. Jasim Raihan

See also "Tools -> Page Info -> Permissions"

Thanks. But, I have Allowed for Send notifications. Unfortunately it is giving the same error message. Did this: Tools->Page Info->Permissions->Send notifications->Allow. Still the same error message: This webpage has been blocked.

Hi, try deleting ALL references to the website in question. To do that, open the 3-bar menu > Library > History, then click the Show All History link at the bottom of the list to open the History-library window. Search for the website you want to clear by typing its name in the Search History field in the top-right corner. Now in the search results, right-click on the site you want to remove, and select Forget About This Site. (Browsing and download history, cookies, cache, active logins, passwords, saved form data, exceptions for cookies, images and pop-ups for that site will be removed). Give it a few minutes to complete the deletion, then try the site (not from an old bookmark) again. More - Delete browsing, search and download history on Firefox.

Try turning off 'Enhanced Tracking Protection' for that site in Firefox by clicking the shield icon at the left-hand end of the address bar - Enhanced Tracking Protection in Firefox for desktop

Disable any ad blocker you may be using then reload the site.

Thanks. I have tried all the above mentioned processes. Not sure what is happening! I have requested my other friends and they can access the site. Whenever, I try to access http://www.mediafire.com/, it is always giving this message: This webpage has been blocked.