Upgraded from IA-2008 to IA-2013, made no changes to the project but while building the project getting below error:

java.io.IOException: Specified Jar File does not exist
at com.zerog.util.ZGUtil.isThisJarSigned(Unknown Source)
at Flexeraam4.ag(Unknown Source)
at Flexeraam4.af(Unknown Source)
at Flexeraam4.aa(Unknown Source)
at Flexeraam4.ac(Unknown Source)
at com.zerog.ia.installer.actions.CustomActionBase.zipCustomCodeSelf(Unknown Source)
at com.zerog.ia.installer.InstallPiece.zipCustomCode(Unknown Source)
at com.zerog.ia.installer.InstallPiece.zipCustomCode(Unknown Source)
at com.zerog.ia.designer.build.ZipToUtility.ae(Unknown Source)
at com.zerog.ia.designer.build.ZipToUtility.installerZipCustomCode(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.zerog.ia.installer.Installer.zipCustomCode(Unknown Source)
at Flexeraadw.a9(Unknown Source)
at Flexeraadw.hs(Unknown Source)
at Flexeraadw.b2(Unknown Source)
at Flexeraadw.fp(Unknown Source)
at Flexeraadw.a4(Unknown Source)
at Flexeraad2.run(Unknown Source)

any leads would be appreciated !!