After exporting some PDFs from GoodNotes, images are missing when viewing them in specific PDF viewers or web browsers.
The same PDFs export properly in GoodNotes 4.
The file format GoodNotes 5 uses to store image information is JPEG2000. GoodNotes 4 used PNG, which had the downside that images could be very large and significantly increased the PDF size when exporting documents. JPEG2000 format has the benefits of small file size, while also supporting transparency like PNG.
The problem is that some PDF viewers do not support JPEG2000 and therefore can't display the images, while others can.
While we're working on a solution to introduce "compatibility", use PDF viewers to display the PDFs that support the JPEG2000 format.
If you have a Mac, you can also open the PDF in Preview and then use "Save As PDF". Then, the images should be properly displayed in other PDF viewers as well.