Add custom external link to menu

Backslashes (\) are not usually used in URL addresses, so WordPress tries to fix it to correct URL.

I’m almost certain that you should use slashes (/) instead:

http://website.co.uk/web1/web2/web3/folder1/folder2/folder3

Then it should all work correctly.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)