The release of PowerPro 2024 brought in the feature of password protection on PDF documents generated by PowerPro
This measure has been implemented as a step towards protecting the AQF documents from fraud

Password protection applies only when editing the PDF document using a PDF editor
Password protected PDF documents can still be printed as any other PDF document 

The password is unknown, as the intent is to make these documents "final" and unable to be altered

This feature affects both AQF and Mail Merge Documents

Should you like to disable this option, you can do so by unchecking the following in Configuration > Application Options > AQF