Sometimes, when Firefox requests a particular site, it responds with a message that the server cannot be found. There are many reasons for this error, from trivial ones to viruses.
First of all, when such an error occurs, you should check whether the requested resource exists at all. Also, check if the internet connection is active.
Sometimes it happens that no website opens at all; in that case, we recommend you check the Hosts file. There might be a virus that blocks access.
Also, sometimes the following helps:
- Open the registry, find the key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\PersistentRoutes
- and clear all its contents.
- In addition, clean the cookies, delete all cache, and restart the computer.
This should help.
We also recommend you read about HTTP statuses, which are very common when such problems occur.
For example, the well-known code 404 means that the requested resource is not found.
- 500 - means there is an error on the server.
- 302 - the resource is temporarily moved.
- 301 - the resource is permanently moved.
For more details about such codes, you can read on Wikipedia, in the article "List of HTTP status codes".
Good luck!
