What causes the issue
The most common cause of this issue is using special characters in your password during the initial installation.
The installation script prompts you for a plain, alphanumeric (letters and numbers) only password. The reason for this is that on a Linux command prompt, certain characters have special meanings that can change the scripts behaviour.
Once AMP is installed and you have access to the web interface, you can change your password to a stronger one that includes special characters.
Fix: Reset the login details via the command line
Resetting your password is done via the ampinstmgr resetlogin command. To run this you’ll need to switch to the amp user.
Switching to the amp user.
If you have access to the root user directly, then you can simply run su -l amp to switch over.
If you’re using an administrator user that is not root (As is typical on Ubuntu for example) then you run sudo su -l amp to switch over.
Applying the password change
Now you can reset the login details by running:
ampinstmgr resetlogin
As with the first time setup script, make sure to use a plain alphanumeric password - you can then change it to a more varied one once you have access to the web interface.
If AMP is not reachable after running this command, start it back up again by running:
ampinstmgr start ADS01