This is trying to read a file prep.ps. But security restrictions means
it can't do that any more by default. If all your files fail, it seems
they may all be trying to read an external file. Alternatively, the
security setting doesn't apply, but you haven't put prep.ps where it
expects to find it. It isn't clear where it should be, this is
nonstandard PostScript.
Not clear whether you can remove this security setting in PDF
Generator.
Aandi Inston