Disabling IPV6 on Always on availability group In our environment we only have one network adapters for the Replicas and IPV4 is being used. By default the IPV6 is also enabled. My question is will there be any problems if I unchecked IPV6 from the Adapter properties
My question is will there be any problems if I unchecked IPV6 from the Adapter properties


Do not disable it, specially if you are not having any issue. WSFC does use IPV6 both for internal communication and can also be used for public network communication. Plus even if you disable IPV6 it is highly unlikely that cluster would not work or start giving some issue. I am sure that even if you disable IPV6 the WSFC would work but may be other network functionality might be affected since network is beyond scope of discussion I am not sure what might be affected but WSFC will work.

I would quote from Failover Clustering and IPv6 in Windows Server 2012 R2 


  Should IPv6 be disabled for Failover Clustering?
  
  The recommendation for Failover Clustering and Windows in general,
  starting in 2008 RTM, is to not disable IPv6 for your Failover
  Clusters. The majority of the internal testing for Failover
  Clustering is done with IPv6 enabled. Therefore, having IPv6 enabled
  will result in the safest configuration for your production
  deployment.