problem exporting to print pdf

What is the content of page 1? What type of graphics did you place?

Below are 3 steps you can try - most common way to fix. 

If the first one doesn't work - then I'd try something else before trying the other 2 options.

Try IDML first.

Then if still not exporting - try export half the amount of pages and see if it exports

Then if that works - try exporting the other half

Whichever half it fails then it's something in that section

Keep halving your output pages until you find the page(s) with the issue(s).

First Thing to Try  ------

If a document is not behaving well then try 

File>Export 

Choose IDML

Open the IDML in InDesign
Save the file as a new InDesign file with a new name
See if the issue persists.

If nothing else is working

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Try resetting your preferences:

Windows: Start InDesign, and then press Shift+Ctrl+Alt. Click Yes when asked if you want to delete preference files.
macOS: While pressing Shift+Option+Command+Control, start InDesign. Click Yes when asked if you want to delete preference files.
A dialog will appear asking to delete the InDesign Preferences, select 'Yes' on this dialog.
Further info and instructions here if needed:
https://helpx.adobe.com/in/indesign/kb/indesign-preferences-support-file-locations.html

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Reinstalling rarely fixes everything - you can do a complete reinstall using the
Creative Cloud Cleaner Tool https://helpx.adobe.com/creative-cloud/kb/cc-cleaner-tool-installation-problems.html