Schematic back annotate error?

Hi,

I am using cadence 16.0 facing a trouble on back annotating the schematic, it gives the following error

{ Using PSTWRITER 16.0.0 s001Aug-07-2017 at 20:02:13 }

Starting the Swp file dumping process ...
Loading netlist files ...
Loading... E:\LAYOUT/pstchip.dat

Loading... E:\LAYOUT/pstxprt.dat

Loading... E:\LAYOUT/pstxnet.dat
packaging the design view...Loading physical design view ...Loading... E:\LAYOUT/funcview.dat
#1 Error [ALG0037] Unable to read physical netlist data.
#2 Aborting Swap file creation... Please correct the above errors and retry.

please help me to resolve it!!!