autoinst.xml gives BTRFS_CREATE_SUBVOL_FAIL

I have a SLES 12 VM that successfully builds from an autoinst.xml file. I wanted to add two volumes, “/var” and '/var/log". Both when I added the four XML lines for each stanza in autoninst.xml and when I just changed existing stanzas, I revieved a “BTRFS_CREATE_SUBVOL_FAIL” and “-15005” errors. Since the lines were cut and pasted via vim, I would guess they are formatted correctly. What do I need to do to fix this?

<listentry>
  <copy_on_write config:type="boolean">true</copy_on_write>
  <path>var</path>
</listentry>
<listentry>
  <copy_on_write config:type="boolean">true</copy_on_write>
  <path>var/log/audit</path>
</listentry>

Update: edited the autoinst.xml to just add “var” and it seems to be working so far.