Manually Reset Delivery Controller

Goto Regedit -

Clear below Registry Entries -

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\DesktopServer\DataStore\Connections\Controller

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\XDservices\ADIdentitySchema\DataStore\Connections

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\XDservices\Analytics\DataStore\Connections

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\XDservices\ConfigLoggingSiteSchema\DataStore\Connections

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\XDservices\ConfigurationSchema\DataStore\Connections

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\XDservices\DAS\DataStore\Connections

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\XDservices\DesktopUpdateManagerSchema\DataStore\Connections

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\XDservices\EnvTestServiceSchema\DataStore\Connections

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\XDservices\HostingUnitServiceSchema\DataStore\Connections

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\XDservices\Monitor\DataStore\Connections

HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\XDservices\StorefrontSchema\DataStore\Connections