Few things you can check:
1. Make sure the share is not formatted with UFS, esx supports only ZFS
2. Try using \ (front slash) 192.168.x.x:\vmware
3. Use vmkping command to check connectivity with particular vmnic/vmkernel to storage
Few things you can check:
1. Make sure the share is not formatted with UFS, esx supports only ZFS
2. Try using \ (front slash) 192.168.x.x:\vmware
3. Use vmkping command to check connectivity with particular vmnic/vmkernel to storage