Technical Note: Unable to create admin user on FortiGate WebUI

When trying to create a new administrator user account, the “Administrator” box was greyed out and there is no way to type in the account name as shown below:

There is no issue when trying to add from CLI.

This issue may occur when there is an idle admin users session running on the FortiGate.  Use the following command to check the admin session list:

# get system admin list

The above screenshot shows that there are 2 idle sessions which seem to be in zombie mode.

Issue the following command in CLI to clear the idle admin session:

# execute disconnect-admin-session      <-- this will list the connected session with index no

# execute disconnect-admin-session <index no>   <-- to clear the admin session

Once the idle admin session has been cleared, admin can create another administrator account from GUI.