When rendering the provided PDF file, the following exception is thrown, causing the PDF to render blank:

FINEST: Certificate chain could not be validated.
org.icepdf.core.pobjects.acroform.signature.exceptions.CertificateVerificationException: Error building certification path: CN=Stadt Zürich, OU=Third Party Services (Art. 9 ElDI-V), OU=Scanning Center Steueramt, O=Stadt Zürich, L=Zürich, ST=ZH, C=CH
at org.icepdf.core.pobjects.acroform.signature.certificates.CertificateVerifier.verifyCertificate(CertificateVerifier.java:98)
at org.icepdf.core.pobjects.acroform.signature.AbstractPkcsValidator.validateDocument(AbstractPkcsValidator.java:634)
at org.icepdf.core.pobjects.acroform.signature.Pkcs7Validator.validate(Pkcs7Validator.java:69)
at org.icepdf.ri.common.utility.signatures.SignatureTreeNode.validateSignatureNode(SignatureTreeNode.java:116)
at org.icepdf.ri.common.utility.signatures.SignatureTreeNode.<init>(SignatureTreeNode.java:73)
at org.icepdf.ri.common.utility.signatures.SignaturesPanel.addSignature(SignaturesPanel.java:167)
at org.icepdf.ri.common.utility.signatures.SigVerificationTask$VerifyAllSignatures$1.run(SigVerificationTask.java:213)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:312)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
Caused by: java.security.cert.CertPathBuilderException: No certificate found matching targetContraints.
at org.bouncycastle.jce.provider.PKIXCertPathBuilderSpi.engineBuild(Unknown Source)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:268)
at org.icepdf.core.pobjects.acroform.signature.certificates.CertificateVerifier.verifyCertificate(CertificateVerifier.java:171)
at org.icepdf.core.pobjects.acroform.signature.certificates.CertificateVerifier.verifyCertificate(CertificateVerifier.java:83)
... 20 more