JFOUD clearly states that it is a seed written on a piece of paper - I doubt that OP is write his private key on paper. It is also very likely that seed is generated by Electrum wallet, just because he/she is try to use same wallet to access his coins.

Also you miss fact that coins are gone after he import seed in Electrum, that means that something has happened after that step - fake wallet, keylogger, malware or anything like that...

Did you verify the signature ?

Even if you download it from the official source, a Man-in-the-middle attack could replace the original client with a malicious one.
Verifying the signature is the only way to make sure you are using the correct version.

If you are too lazy to verify the signature, at least check the hash of the file.

To check the hash, please do the following (assuming you are on windows):

• Open the command promt (WIN-key + R  -> then enter 'cmd')
• Enter: certUtil -hashfile C:/path/to/your/electrum/file.exe sha256

Then please post the output here and tell us which version of electrum you are using. I am then going to download the correct file and verify that the hash is the same.
If this is the case, your client was non-malicious and we have to look further how your coins got stolen.