Assure error

hi there, could anyone please help me out with this
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Loading tech rule set file : /root/raheem/cadence_tools/scratch/TSMC_18/cadence_tsmc18/Assura/techRuleSets
Initializing from libInit.il for library tsmc18...
-- pcell18v1a.cdn
-- tsmc18_updateCDFs.ile
-- tsmc18.cxt
Loading Working place Display File '/root/raheem/cadence_tools/scratch/TSMC_18/cadence_tsmc18/display.drf'
Compiling rules...

WARNING Connected layer 'ntap' is being used as via in geomStamp.
WARNING Connected layer 'ptap' is being used as via in geomStamp.
WARNING Connected layer 'ptap' is being used as via in geomStamp.
WARNING Connected layer 'pplug' is being used as via in geomStamp.
WARNING Connected layer 'pplug' is being used as via in geomStamp.
WARNING Connected layer 'pplug' is being used as via in geomStamp.
WARNING LVS Run detected.
Non-legacy mode has been disabled for this LVS run

Reading the design data...



Finished dfIIToVdb.

Building the VDB part 2 in background mode.

Building tables for LVS Preprocessing in background mode.


Starting /root/cadence/ASSURA41OAISR_lnx86/tools/assura/bin/vdbToCells . inverter_rf

Finished /root/cadence/ASSURA41OAISR_lnx86/tools/assura/bin/vdbToCells

Starting Nvn PreExtraction...

Starting /root/cadence/ASSURA41OAISR_lnx86/tools/assura/bin/nvn /root/raheem/cadence_tools/scratch/TSMC_18/cadence_tsmc18/inverter_rf.rsf -preExtract -exec1 -libdefs /root/raheem/cadence_tools/scratch/TSMC_18/cadence_tsmc18/lib.defs -cdslib /root/raheem/cadence_tools/scratch/TSMC_18/cadence_tsmc18/cds.lib
@(#)$CDS: nvn version av4.1roduction:dfII6.1.3:IC6.1.3.500.10 09/25/2009 12:47 (sfrh49) $
sub-version 4.1_HF3, integ signature 2009-09-25-0853
run on localhost.localdomain at Tue Mar 24 15:39:48 2015
WARNING (AVLVSNN-10029) : 'filter' command has been converted into 'filterOptions' with the same function. 'filter' command is not supported. Use 'filterOptions' instead.
Reading schematic network
inputting netlist /root/raheem/cadence_tools/scratch/TSMC_18/cadence_tsmc18/Assura/lvs_rcx/source.added
Reading layout network
inputting network inverter_rf.ldb
Error: rootCell(or ?cellName) - cell 'inverter_rf layout invertr' from the layout does not bind to anything in the schematic.

*WARNING* /root/cadence/ASSURA41OAISR_lnx86/tools/assura/bin/nvn exit with bad status
*WARNING* Status 256
*WARNING* Assura execution terminated

Finished /root/cadence/ASSURA41OAISR_lnx86/tools/assura/bin/nvn

*WARNING* An error occurred during Nvn PreExtraction.
LVS preprocessing requires a successful run of Nvn.
Assura will now terminate.

*WARNING* Bad exit from child process .. 0x100


***** aveng terminated abnormally *****


*WARNING* aveng exit with bad status
*WARNING* Status 256


***** aveng fork terminated abnormally *****

*WARNING* Assura execution terminated