PDF/A standard

Everytime I save a pdf file after filling it's acrofields I open it on Acrobat Reader, there's always a message saying:
"This file claims compliance with the PDF/A standard and has been opened read-only to prevent modification"
Before using the file with Radaee, the pdf didn't show that message.
Can you explain why that happens? Can and should I disable that?
I have the feeling this is impacting when I want to read acrofields values after saving the file. But it might be just me.

last beta:
www.radaeepdf.com/forum/roadmap-and-rele...viewer-sdk-3-55beta2
already remove PDF/A header generation.
using this version to save PDF file, won't report readonly message.

to make PDF/A header can only enable for master edition in future.