When I'm trying to export a indesign file to pdf I get a message saying the file can't print tp pdf due to an unknown error. I have just upgraded my indesign to the 2017 version, I've saved the same file to pdf heaps of times Before this. Does anyone know what the problem might be?
Are you trying to print to PDF using the print dialogue or instead using the Export/Adobe PDF presets dialogue?
Start with basic troubleshooting steps:
Export as IDML (File > Save As > InDesign CS4 or later), then reopen and try again to eliminate corruption.
Or: Restore your InDesign preferences: