I tested an older version of my app in the same folder, where the PDF does load.
This app was built on 25/11/2024, which was prior to the current version.
I'm a frequent updater, meaning mostly I update only a few days after the release. So I presume I had installed the latest update available via Smart Setup.
I'm Using Delphi 12.2 on Windows 11 ARM. It's a VCL 64-bit app.
The last modification applied to TTMSFNCWXPDFViewer was in april last year. TTMSFNCWebBrower didn't receive any updates that would interfere either, so it must be something specific to your enviroment/application.
We don't have a Windows 11 ARM available but we made a small test with Delphi 12.2 on Windows 11, targeting Win64 from a VCL app. Loading from base64 works as expected here.
Assuming you made no changes to the application, can you check the following:
Are other WX controls working as expected (e.g. TTMSFNCWXQRCode)?
If you separate TTMSFNCWXPDFViewer into a new application, does it load the base64 PDF?