Hello
I am very new to this. It seems my website has a mind of its own and 'breaks itself' by all accounts!
I can no longer add or amend any of the menus under the 'Nav bar'. I continue to get the below for a new menu item when you choose from the select dropdown box
JFile: :read: Unable to open file: /var/www/web/templates//layout/default.json
When you try to amend, you get a screen that I am unable to amend or save
Joomla! 2.5.28

This file -> /var/www/web/templates//layout/default.json is not a part of K2.
The file path indicates a template or a 3rd party extension issue.

Thank you for your reply Krikor. Is there no way to get around this as the guy that designed the website is unable to understand what is going wrong with it and cannot fix these issues.
That error message appears when I select the virtuemart category. If I choose K2 'categories' will this solve the issues?

Unfortunately I cannot assist you on this issue since it is related to virtuemart.