I was a able to add JPEG attachment to a customized page status::Open and also preview the JPEG attachment in the status::Pending Approval while send for approvals.
But I was unable to add PDF attachment to a customized page, status::Open, CAL.
You need to say a bit more if you want anyone to help you with an answer to why you customized page does work....
I added a button on the page action of my customized page called Attach PDF. When I click the Attach PDF button, it will open for attach pdf in the system. I need how to write the C/AL for attach pdf. I only know the ones for attach JPEG.