Ok, I think this is NOT any issue with the PDF. I have an LG tablet, and using the desktop PC to view files on the internal storage via USB connection. This part seems to be going brain-dead sometimes, and is not seeing up to the moment picture of what is stored on the tablet. When I rewrite the PDF file, then sometimes it reflects the up-to-date version, and sometimes I see it, but what it brings to PC when copying is junk. No errors reported in that process, it just pulls a corrupt file. I resolved this issue by disconnecting the tablet from PC, and reconnecting, THEN pulling the latest file, and these are coming out beautifully. First time to deal with this gotcha that has nothing to do with B4A or ANDROID.