The third party PDF generator used in FTM since version 2008 is PDF standard 1.3 that has a size limitation of 5 metres (about 200 inches). The developers are well aware of this annoying limitation.
Adobe has long since taken away this limitation in PDF but for reasons that have never been made clear, the third party developer that supplies the Share module to FTM, which includes the PDF printer, has stuck with ye olde PDF 1.3.
I would suggest that you look at an outside charting package and Family Tree Factory is perhaps the best for very long charts. Another option is Charting Companion.
Both are around USD 30 each to download
John D
Adobe has long since taken away this limitation in PDF but for reasons that have never been made clear, the third party developer that supplies the Share module to FTM, which includes the PDF printer, has stuck with ye olde PDF 1.3.
I would suggest that you look at an outside charting package and Family Tree Factory is perhaps the best for very long charts. Another option is Charting Companion.
Both are around USD 30 each to download
John D