You may want to create the data store manually. I've had a few installs that have had a similar problem. On your system you may need to update the references to sda and vmhba0:0:0:10 to match the setup of your system.
FDISK - creating a new disk with VMKFSTOOLS
Run fdisk -l to see devices
Run fdisk /dev/sda
If you have to add a VMFS - create the partition (n) then change the type (t) to fb. Then (w) save the changes.
Check fdisk /dev/sda again and list partitions (p) - it should list as fb.
If so , exit and run vmkfstools -C -S "datastore_name" /vmfs/devices/disks/vmhba0:0:0:10