#33 java.lang.NullPointerException at iteratePages

[echion]

Hi - I'm getting this error trying to sign a v1.6 PDF; any ideas what could be
the problem?

$ java -jar JSignPdf.jar input.pdf -V -c "Joe Bloggs <jb@example.com>" --img-path signature-transparent.jpg --keystore-file ~/keystore.p12 --keystore-type PKCS12-3DES-3DES --keystore-password "password" --out-suffix -signed
DEBUG Relaxing SSL security.
INFO Checking input and output PDF paths.
INFO Getting key alias
INFO Used key alias: XXXX
INFO Loading private key
INFO Getting certificate chain
INFO Opening input PDF file: input.pdf
ERROR Problem occured
java.lang.NullPointerException
at com.lowagie.text.pdf.PdfReader$PageRefs.iteratePages(Unknown Source)
at com.lowagie.text.pdf.PdfReader$PageRefs.readPages(Unknown Source)
at com.lowagie.text.pdf.PdfReader$PageRefs.<init>(Unknown Source)
at com.lowagie.text.pdf.PdfReader$PageRefs.<init>(Unknown Source)
at com.lowagie.text.pdf.PdfReader.readPages(Unknown Source)
at com.lowagie.text.pdf.PdfReader.readPdf(Unknown Source)
at com.lowagie.text.pdf.PdfReader.<init>(Unknown Source)
at net.sf.jsignpdf.SignerLogic.signFile(SignerLogic.java:146)
at net.sf.jsignpdf.Signer.signFiles(Signer.java:231)
at net.sf.jsignpdf.Signer.main(Signer.java:127)
INFO Finished: Creating of signature failed.