Although folder permissions set to 777 and later 666 and all necessary files are in the folder, image gallery add-on throws error "• Upload ErrorThis folder is not authorized for upload!Please make sure it has write permissions and the authorization file is in it."
Page link: www.wvdemiddelsee.nl/content/contact1.php
Permission:

Hello,

Please send me the login details to:

Hello,

I see you are using OLD jquery version: <script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
Instead of the jquery provided by us, which is the latest version (1.10.0)
Please use the one provided with the extensions, as it is the latest one.

They were both in there because of some extensions being updated and others not yet. This particular page now only has 1.10.0 in it, but still no joy

Hello,

This now seems to me like a permissions problem. Please check if you have any .htaccess file that has any restrictions in it.

Through server file management I deleted the folder. Made a new folder, changed permissions. Now it is working.