Here are some things to try:
Make sure you have the correct address for the webpage and that you typed it correctly.
Try entering “/index.html” at the end of the address.
Empty the cache, and then try reloading the page. To empty the cache, choose Safari > Empty Cache, and then choose Empty.
Contact the website’s owner and ask:
Does this webpage prevent access by the Safari browser?
Is the first part of the address, which identifies the Internet protocol (such as http or https), nonstandard? If it is nonstandard, Safari can’t open it.
Is the link to the page trying to open a file in another application? (If the file or application isn’t available, you’ll get a message saying Safari can’t open the URL or file.)
Is there a problem with the server’s configuration?