You have forgotten the Citrix ADM nsroot password and you need to reset it. The procedure to reset the password for Citrix ADM might differ on hypervisors where it is hosted. If you have changed your default password and want to reset to default password, you can reset the password by rebooting the Citrix ADM node.
The solution is provided step-by-step in the following Citrix article:
A different process is used for the following major hypervisor platforms:
- Citrix XenServer
- VmWare VSphere
- Microsoft HyperV
- Linux KVM