Thank you for your interest in Syncfusion products.
We are able to reproduce the issue with deploying the application with the Pdf Viewer control. The issue occurs while deploying the application with culture settings other than the “en-US” culture. The fix for this issue will be available in our upcoming release. As a workaround, please do change the Default language value to en-US, to get this sample working. Please find the snapshot available below. We have also attached the sample in which the correction is made.
Please note, the build configuration of this project was Any CPU, and it needs to either X86 or X64 or ARM, this change is also included in the sample available in the link below.
Sample link: GappTestPdfViewer_Updated.zip
Please let us know if you have any concerns.
Sorry for the inconvenience caused.
Please find the screenshot available in the link below for the change to be made.