This isn’t technically a problem unique to DevonThink, but I haven’t been able to figure out where else to find an answer. The problem I have is that I can’t copy text from a PDF. Occasionally, there are exceptions, but in many cases (for instance, any PDF that comes from the JSTOR archive of academic journals), there’s no way I can copy text. It doesn’t seem to make a difference whether the text is digitally-produced or OCRed, nor whether I use Apple-C or pick Copy from a menu. I know that the text is really there, because I can find it by searching. The same thing happens if I open the PDF in Skim. Is this a known problem? Is there any way around it?
They may have a security flag set to prevent copy/paste.
If not, have you tried converting the file to a rich text in the DTPO contextual menu? That might do it.
Otherwise, try the “recover text from any file” script in the script menu.
“Recover Text From Selected File” is a service installed with the freeware Bean rich text editor. It’s a nice little program in its own right. See it here: bean-osx.com/Bean.html