PDF export error: "We can't open this file, something went wrong."

[ali_4619]

Unfortunately, for the first time in six months of using InDesign, I am suddenly getting an error message every time I export my book as a PDF for a final proofread. It says either: "Error failed to load PDF document." OR: "We can't open this file, something went wrong." I have tried 20 times with different versions of the book. I regularly save new versions to creative cloud and have only had the problem today after uploading my CMYK pics. Yesterday they were RGB so I had to change them for the printer. I have restarted my computer. Uninstalled and reinstalled InDesign. Also suddenly InDesign won't accept me changing the units from inches to mm. It l ets me do this once in document setup and I save the change. But when I go back to document setup  to double check, it has reverted to inches. When I try to change to mm in a specific document, it allows me to enter mm only in the width box and then when I move to the height box, it reverts back to inches. I did not have this problem for six months. Since reinstalling isn't working, I'm at a loss to know what to do. By the way, you will see from all my tabs at the top of the screenshot, I am doing my best to learn everything myself. 

[ali_4619]

PS: Extra info in addition to my post above - that error message in screenshot was in Chrome PDF reader. So I downloaded free acrobat and I get this error message: 

[Willi Adelberger]

I am confused. Your problems are with a PDF, but a book file consists of INDD files. Where comes the PDF?

Why did you convert your images to CMYK mode?  Let them in RGB. Converion should be done not before PDF export. When you export PDFs you can choose an output profile  Where the convertiion is done should not bother the printer. 
Google Chrome is not a valid PDF viewer. PDFs should never come in contact with that program. 
When you import PDFs into InDesign, they should always be PDF/X-4. 

[ali_4619]

Hi thanks Willi. The printer told me it would be the best result to convert individual images to CMYK. Also they want me to send them an InDesign package rather than just a PDF. I wanted to export the InDesign file as a PDF to do a final proofread before I send the package. I find PDF helpful to look at since it is very clear and I spot things I didn't notice in InDesign. But adding the CMYK version of the photos appears to have caused the InDesign document to be corrupted. I have tried 12 times today adding CMYK then RGB photos in different versions of the InDesign file I saved both on my computer and within Creative cloud but when I do test exports to PDF while working through I get the error messages. I'm sorry this isn't easy to explain. I have spent hours on this today and feeling at such a loss. I feel I might have to start the whole book from scratch but it's 40 pages long.

[Willi Adelberger]

1. InDesign and Photoshhop use the very same Adobe Color Engine. It is installed once for all applications. With the same setings you get the same results., In Photoshop you should use the CMYK print preview.
2. Never send any open file to the printer. Make a PDF which meets the printer's requirement. An open file can change, if the printer uses different fonts or a different user dictionary. You are not even allowed to send fonts or many linked assets due to license restrictiions.
3. I do not understand where your PDFs come from.

Find a different printer.

[ali_4619]

Thanks again. That's all great to know. I would just send a PDF to the printer but that's the problem. When I try to export my InDesign file as a PDF, I get the error messages.

[Daniel Steiger]

As I can see, you works on a Windows system. I assume that there is also something similar to a cache there.

On Mac there is the user library with the directory Cache. In it a folder called InDesign. This can be deleted without hesitation. It is automatically rebuilt. Try to find it on Windows to delete. Maybe that will help.

[Robert at ID-Tasker]

@ali_4619 

Can you try exporting separate INDD files.

If it will work - then, as a last resort, you could join them together in Acrobat.

As @Willi Adelberger suggested - NEVER EVER give open INDD files to your printer - find another one asap.

And their request to convert RGB -> CMYK is because they want you to be responsibe for the color conversion - which wouldn't be necessary if they would accepted print ready PDF - and had some proper RIP software - not some ancient relict.

The next request from them will be for you to outliine all texts??

Depends on how much time you have - we can try to help you diagnose the problem - or you could try a "Nuclear" option described here - or you can try all other steps first:

https://community.adobe.com/t5/indesign-discussions/reset-indesign-preferences-and-other-troubleshoo...