What can be the reason for this kind of error while signing a document?

[DunklerPhoenix]

Heho
I get this error if I try to sign a document:

server-1     | new entry is insert in contracts_Document
server-1     | Err in signpdf TypeError: Cannot destructure property 'publicKey' of 'certBags[i].cert' as it is null.
server-1     |     at /usr/src/app/node_modules/@signpdf/signer-p12/dist/P12Signer.js:66:9
server-1     |     at Array.forEach (<anonymous>)
server-1     |     at P12Signer.sign (/usr/src/app/node_modules/@signpdf/signer-p12/dist/P12Signer.js:64:27)
server-1     |     at SignPdf.sign (/usr/src/app/node_modules/@signpdf/signpdf/dist/signpdf.js:72:30)
server-1     |     at PDF (file:///usr/src/app/cloud/parsefunction/pdf/PDF.js:405:38)

Do you know what the problem with my certificate could be? Can't it be openend? Is it the wrong type?

It is a certificate signed by a CA which I control.
Greetings
Cy

[DunklerPhoenix]

I created a local certificate request and signed this one. It worked. I don't know why it can't read the pregenerated certificate

Edit: It is definive a problem with my certificate. The used library has problems with additional certificate features. I generated a new one with CRL informations and get a out-of-bound pem error. :D

Edit2: A certificate with integrated certificate chain is also not supported