You are attempting to vMotion a VM, likely using the vSphere web client and likely trying to change host and storage.
/var/log/vmkernel.log on the source ESXi host is showing errors. Specifically this error:
2016-09-24T14:39:57.638Z cpu5:34608)FSS: 5914: Failed to open file ‘vmware.log’; Requested flags 0x2, world: 34608 [vpxa-worker] (Existing flags 0x5, world: 76640135 [vmx]): Busy
/var/log/host.log one source ESXi host is showing that the source machine is an IPv6 IP and the destination IP is an IPv4 IP. Like this:
40B70 info ‘Vmsvc.vm:/vmfs/volumes/562578d3-39000d7a-8011-blah/Analyzer/Analyzer.vmx’ opID=78d0fdec-95-54 user=vpxuser] VMotionPrepare: srcMgmtIp=2607:0000:6:8:225:9999:fe00
40B70 info ‘Vmsvc.vm:/vmfs/volumes/562578d3-39000d7a-8011-blahe/Analyzer/Analyzer.vmx’ opID=78d0fdec-95-54 user=vpxuser] VMotionPrepare: dstMgmtIp=188.8.131.52
Fix your IP issues. Vcenter has added one of your host with its IPv4 address and the other host with its IPv6 address. Temp fix is to disable IPv6… Long term… fix your IPv6 issue (remove re-add host).