Can you try opening https://electrum.org/version using your normal browser? You should be prompted to download the file 'version'. If you open this file using an ascii editor (like notepad++, vim,...) you should see a json string containing (amonst others) the current latest version.
If this doesn't work, you know what to investigate... If this works properly, the problem must be something else, for example: are you using the tor proxy?
Yeah I know I have last ver but I just want to know why i get update failed? When I was click (before) on check for updates I get message > you have last update.