PDFTron Annotations are disappearing

Product: PDFTron.UWP NuGet Package

Product Version:

Please give a brief summary of your issue:
PDF annotations disappear as more annotations are made.

Please describe your issue and provide steps to reproduce it:
One of our clients have come across an issue while using PDFTron where as they write, some previous annotations they have just made will disappear.

Just using our app, and using PDFTron to annotate a pdf, we find that, inconsistently, when writing numerical values exclusively 0s and 8s disappear.


Can you provide a sample project and PDF to reproduce this issue? I am not able to reproduce this issue, making it difficult to assist.

Perhaps the annotation’s bounding box is being cut off? As the user taps to write more, the annotation saves and applies to the PDF.

Simple Sample with just PDFTron viewer. I have managed to recreate this issue with any PDF, thus you can use the File picker to select any PDF you may have. The PDFViewer is very barebones compared to ours, but it is sufficient to recreate the issue.

Sample Project Zip file:

Video of Sample with issue:


Thank you for the additional information, we will investigate when we can.

This is also something that I have come across in the PDFTron UWP Demo Sample provided by PDFTron on Github:

PDFTron/pdftron-uwp-samples (github.com)

Thus it is most likely a PDFTron issue. It would be great to have this investigated as soon as possible.

Issue recreated: