Compliance of a cluster is checked based on various factors, depending on if you have HA enabled, DRS enabled or both!

• FT logging NIC speed is at least 1000 Mbps.
• At least one shared datastore exists.
• FT logging is enabled.
• VMotion NIC speed is at least 1000 Mbps.
• All the hosts in the cluster have the same build for Fault Tolerance.
• The host hardware supports Fault Tolerance.
• VMotion is enabled.

DRS only

• VMotion NIC speed is at least 1000 Mbps.
• VMotion is enabled.
• At least one shared datastore exists. 

HA only

• FT logging NIC speed is at least 1000 Mbps.
• At least one shared datastore exists.
• FT logging is enabled.
• VMotion NIC speed is at least 1000 Mbps.
• All the hosts in the cluster have the same build for Fault Tolerance.
• The host hardware supports Fault Tolerance.
• VMotion is enabled.

The most common problem is that when HA is enabled on a cluster (with or without DRS enabled) one requirement is "FT logging is enabled".

FT (Fault Tolerance) is not that widely used so the chance you set this up is unlikley (and is not require for HA to work) so this is a bit a false check as we might not want FT!

To disable the checking of FT for the cluster complance check this is simply and advanced option in the HA settings..

1. Simply right-click Edit Settings on your cluster

2. Select vSphere HA and click the "Advanced Options" button

3. Enter the option "das.includeFTcomplianceChecks" and a value of "false".

4. Click Ok, Ok.

5. Rescan you cluster for compiance and hey presto!