Issues Saving Ark Media Configuration
By default Joomla comes with nine user groups and each come with their own set of permission parameters, as seen below:

Adding more user groups, adds more parameters to the form and adding a large number of user groups, could result in the maximum amount of form fields your server allows, being exceeded. If this happens, the server will block the submission of the Ark Media Configuration form, resulting in you being unable to save Ark Media's configuration. The solution would be to increase the server's maximum allowed input variables.
To do this:
- Find out the current server maximum field value, by navigating to 'System' and clicking on 'System Information'. Then, under the 'PHP Information' tab, use the browser's search (Ctrl + F) to search for 'max_input_vars' which will contain the current server maximum field value.
- Using FTP, navigate to your Joomla installation's 'administrator' folder and edit the 'php.ini' file that is in this directory, by adding the following parameters to the first two lines/settings, increasing the server maximum field value, to the desired value (we have used a value of '2000'):
max_input_vars = 2000;
suhosin.post.max_vars = 2000;
suhosin.request.max_vars = 2000;
You should now be able to save Ark Media's configuration.
Alternatively, if you do not wish to set the php.ini rule, you could review your user groups and condense some similar groups and delete old or unused groups, to reduce the size of the form.