Shared nothing vSphere vMotion was introduced in vSphere 5.1. With this release, the Web (Flash) client became the primary client and all, well pretty much all new functionality was then only exposed to the Web Client.
You will be able to migrate both the host and the datastore if you use the Web Client.
Please find answers in bold, it seems more of a feature issue as it is greyed out straight away
- The hosts must be licensed for vMotion. - Enterprise Licensed
- The hosts must be running ESXi 5.1 or later. - ESXi 6.0U1
- The hosts must meet the networking requirement for vMotion. See vSphere vMotion Networking Requirements. - vMotion Enabled
- The virtual machines must be properly configured for vMotion. See Virtual Machine Conditions and Limitations for vMotion. - Do not see any issue
- Virtual machine disks must be in persistent mode or be raw device mappings (RDMs). See Storage vMotion Requirements and Limitations. - Default disks (Persistent)
- The destination host must have access to the destination storage. - Yes a local datastore on each host
- When you move a virtual machine with RDMs and do not convert those RDMs to VMDKs, the destination host must have access to the RDM LUNs. - N/A
Are you running vCenter on Windows or are you running the vCenter Server Appliance? (I would guess you'd be running the Windows version of vCenter.
This KB article might help... VMware Knowledge Base
If running Windows, then to restart the Web (Flash) client service...
- Open Server Manager on the Windows system on which vCenter Server is running.
- Click Configuration > Services.
- Select VMware vSphere Web Client and click Restart.
KB article helped as restarted web client service via CMD and it eventually loaded via IE (and no shared storage migration worked)