Thread:Extension talk:WYSIWYG/getimagesize error in CKeditorLinker.php/reply

$url which your system returns, must be somehow different than mine, because my system requires '/../../..'.

What is absolute value of your "image" directory?

What is absolute value of directory where file CKeditorLinker.php is located in your system?

Can you also tell me how you have set up variable $wgUploadDirectory in your LocalSettings.php?