page numbers can have value "auto"
StyleParagraphPropertiesElement.getStylePageNumberAttribute() may throw a NumberFormatException when page number has value "auto", which is a valid value according to https://docs.oasis-open.org/office/v1.2/os/OpenDocument-v1.2-os-part1.html and https://docs.oasis-open.org/office/OpenDocument/v1.3/os/part3-schema/OpenDocument-v1.3-os-part3-schema.html
I had to use the XML API to read the attribute directly to prevent that exception as workaround.
@svanteschubert can't assign ticket to you as requested
@winterrifier My bad, I was tired! :-)
As mentioned in https://listarchives.odftoolkit.org/dev/msg00110.html This is a generation error that I have been working on - refactored complete generation -, but it is unfinished business. I will aim to switch to it soonish and give you at least a status on what is blocking and a chance to participate. Sorry for the delay..,