Help me on performing an LVS with Calibre

Help me on Calibre LVS

I want to do LVS on Calibre .
I have done my Layout in Virtuoso .
While doing LVS i am getting the following errors.

In Transcript file

"WARNING: XDB Database not available: No comparison was made.
Unable to restore XDB database.
NOTE: Cross reference commands will be unavailable since a valid cross reference (XDB) database was not found."

In LVS Report:
"WARNING: Invalid PATHCHK request "GROUND && ! POWER": no POWER nets present, operation aborted.


WARNING: Invalid PATHCHK request "POWER && ! GROUND": no POWER nets present, operation aborted.


WARNING: Invalid PATHCHK request "! POWER && ! GROUND": no POWER nets present, operation aborted.


WARNING: Invalid PATHCHK request "! LABELLED": no LABELLED nets present, opera

Error: Different numbers of ports (see below).
Error: Power net missing in layout. Ground net missing in layout."

In ERC also i am getting errors of CHECK wrong FLOATING NTAP,etc

I gave input to Calibre LVS as gds2 generated from (CIW->export->stream).