Hi, just thought I ought to share my solution to the problem I had with an InDesign file that stopped exporting to PDF.

I was getting the background task throwing up an error towards the end saying there was a problem and that it couldn't finish. The file I had been working on had been doing a few odd things and I have had one or two crashes which I think had slightly corrupted the file.

I checked I could still export from a known to work file and yes, I could still export that, so I suspected it was the current file being corrupt causing the problem rather than an InDesign/Acrobat issue.

What I did, and useful I think for whenever you suspect file corruption, is to File/Export the file as an 'InDesign Markup (IDML)' file. After that's done, close the current file and then File/Open that new IDML file and it will reimport everything and this will hopefully fix your corruption. All styles, colours, etc., are still intact, all exactly the same as before.

Not exactly sure how it works, but the IDML export obviously cleans up the file along the way. It just worked for me and the file will now export to PDF again.

Hope that helps someone, regards to all.