The file eventually loads but there are lots of negative index error messages so I am wondering if the OpenVDB sample from the original folks creating the OpenVDB format have some convention that is different from how Paraview is loading the file ?
Your dataset contrains two blocks, and each block has only one of the result (temperature or density), which triggers the error when you ask ParaView to render one of the field on the whole domain.
To avoid the errors, you may extract each blocks and display them separately. Eventually you may resample one block on the other to get one dataset with two fields at the end.
Beside these tricks, I don’t know if this block approach is common with VBD datasets. Maybe @Lucas_Givord or @mwestphal would have some hints there?