You’ve updated your linked-clone pool’s master image and attempt to reassign the Default Image Snapshot but while you are able to assign the new snapshot, you receive the following error when you try to apply the setting:
Active Directory Host Unreachable
While there can be several reasons why this error would be thrown, this is usually caused by connectivity issues between the server with the View Composer role installed and your Active Directory controllers. In the example above, I noticed that the vCenter server which had the View Composer role installed was assigned a primary and secondary DNS server that would not be able to look up the internal Active Directory domain zone which would prevent the View Composer role to locate and communicate with the Active Directory Domain Controllers. The error above went away as soon as I removed those DNS servers and configured the primary and secondary servers to point to the Active Directory Domain Controllers which had DNS installed on them.