During the process of building an Azure lab, I ran into a place where my cluster was not completely validated. I think this happened when a node failed and was re-provisioned, but in any case, when I ran SQL Server setup, the program failed cluster validation and would not install.
If you find issues, try the command line to start setup. This is what I did. For the first node, I ran setup from the command line like this:
Setup /SkipRules=Cluster_VerifyForErrors /Action=InstallFailoverCluster
The same GUI popped up, and I was able to set various settings and save my config file.
For the other nodes, I ran this:
Setup /SkipRules=Cluster_VerifyForErrors /Action=AddNode
Pretty simple, the platform installed and worked fine. Whatever cluster issue I had must have been transient, at least for my lab purposes.