NFS Datastore mount error in vSphere6 with Synolgy NAS

In my home lab I would have tried to measure what is different between iSCSI and NFS datastore. (I/O Analyzer)
I use esxi vSphere6 and Windows base vCenter 6. My storage is Synology ds414j (DSM 5.2-5565).

I have crated new NFS shared folder, but before i did this i had switched on NFS service on my NAS.
When i added new NFS Datatstore to ESXi host, i got error message, you can see below.



I loged into directly to ESXi host by vSphere Client and I added NFS Datastore, it worked fine.



Yes I know, this is just only a “workaround” solution, and it’s workin in lab environment.
I share my experience with you becose, I would like help to somebady who have same problem, and looking for any solution.