I have a user who, all of a sudden, has started creating .jdf files instead of .pdf files when exporting from InDesign CS5. It was working fine yesterday, but then this morning (after restarting a couple times), it still won't make a .pdf. I've checked her settings, everything is the same as she had before. I can't find anything on this subject, so hoping someone else had (has?) this issue and can help. I"m hoping I won't have to reset her InDesign preferences, but I don't think that will fix the issue either.
I see nothing there to indicate that InDesign created that file.
Because you're using an older version of InDesign CS5 and Acrobat X Pro, there is still a feature available that can generate a JDF file.
If you look at this help file, you'll see a choice under the Advanced areas of the PDF Export Options:
"Create JDF File Using Acrobat
"Creates a Job Definition Format (JDF) file and starts Acrobat Professional for processing the JDF file. A job definition in Acrobat contains references to the files to be printed as well as instructions and information for prepress service providers at the production site. This option is only available if Acrobat 7.0 Professional or later is installed on your machine. For more information, see Acrobat Help."
This is an out-of-date feature which has been discontinued as describe in this posting: