Robert, Joel, and Rishabh - Thank you for your suggestions. I tried Rishabh's suggestion saving as IDML, opening and resaving as INDD. This worked! Thank you! This also creduced the file size from 33MB to 21MB with no loss of data or issues that I can see. Love to know why this worked. Maybe Adobe can add this to the next update and improve their INDD save process?
Robert, Joel, and Rishabh - Thank you for your suggestions. I tried Rishabh's suggestion saving as IDML, opening and resaving as INDD. This worked! Thank you! This also creduced the file size from 33MB to 21MB with no loss of data or issues that I can see. Love to know why this worked. Maybe Adobe can add this to the next update and improve their INDD save process?
By @mgsummer
You are probably only using Save, right?
When you work on your document - InDesign is constantly adding Undo History so you can go back to an empty document - untill you close it.
When you do Save - all this info is preserved in the file - but when you close your document - it stays there but isn't accessible anymore - so your file is getting bigger and bigger and is getting slower to open and work.
When you do Save As - with a new name - InDesign is removing this Undo History.
IDMLing is even deeper housekeeping - it also purges all previews.
When you open IDML file - InDesign is rebuilding it from scratch.
This also helps to fix corrupted documents.
You can use Save as often as you want - but you should do Save As with a new name at least once a day.
This has two benefits:
1) removes Undo History so your file will open quicker,
2) you have a backup copy.