PDFs Have Suddenly Stopped Displaying

[TimSchofield]

I suspect there is some white space being output.

It may be that you are hitting a problem I have warned about for some time. Some developers have taken to leaving blank lines at the end if scripts after the final ?>

This means that when a script is run a blank line is output meaning that the error you mention will be output. My guess if it is occurring in each pdf output then it is a script that is common to all of them. I don't have the code in front of me but I would check class.pdf.php sessions.inc and the ConnectDB scripts.

Tim