Hi @healthfirst
Please remember that the filter ‘the_content’ shoudl only ever be run on the front end of the website.
I don’t know what ‘tab_content’ is, but it sounds like it should be in the admin.
Please use the correct filter depending on your ACF version and always debug your code to test if it is working / not working
http://www.advancedcustomfields.com/resources/how-to/debug/
