Indexhibit Support

Admin section disappeared after password reset
Found an old thread that advised:

Fixed. Download this file and replace /ndxzstudio/module/system/index.php.

Login to your site, then visit this url and it will clear things up...

yoursite.com/ndxzstudio/

however this did not work. PHP 5.6. Updated website earlier too.

So, to fix this:

1) Access your database via phpMyAdmin or a similar tool in your hosting.
2) Go to the "ndxz_users" table (your table might have a different prefix instead of "ndxz_")
3) Change the "user_admin" column of your user from 0 to 1.

Now, the Admin link should appear again.

Regards

Source:
indexhibit.org/forum/thread/23080/

Thanks for your help Frami - I've fixed this now

I spoke to soon. The Admin link has reappeared but now when I click on it I am directed to a blank page with the message - " This page isn't working - HTTP ERROR 500 ". I also receive the same message when I click on the 'Preferences' link and 'Logout' link - the 'Help' link works fine.

Try putting in your old index.php , like before.
/ndxzstudio/module/system/index.php

try passing php 7.xx?