Shared VHD on SOFS - cannot initialize in guests.

Hello,

Trying to create cluster of VM guests on hyper-v cluster.

Have SOFS (clustered storage spaces) server for HYPER-V cluster. In cluster i have two VMs. I create VHDX on SOFS share and connect it to VM's on the cluster and enable virtual hard disk sharing.

Shared disk in VM's are displayed as "Not Initialized". I try to initialize it and get error : The request could not be performed because of an I/O device error.

and in event log error is : VDS fails to write boot code on a disk during clean operation. Error code: 8007045D@02070008

if i uncheck "Enable virtual hard disk sharing" and try to initialize it - it works. But after enabling virtual hard disk sharing disk is displayed as Not initialized and i can't initialize it. 

What can be wrong with my SOFS server?