When you're having problems with a specific file, it generally comes down to either minor file corruption or a specific element that's been placed in it.
The fastest way to sidestep the issue, in most cases, is to clean and simplify the file. You can try that as follows:
Instead of saving the file, use the File>Save As... menu command. In the Save as type: options box, change from the default InDesign XXXX document (*.indd) option to InDesign CS4 or later (IDML) (*.idml) option, then click the Savebutton. This saves a copy of the document in an Adobe-defined version of an XML document which refines, and slightly re-defines, the InDesign document.
Close your original InDesign document.
Then go to the File>Open menu command and navigate your way to the [SameFileName].idml file you just created, and open it.
When the file opens, you'll notice in the document tab that it's named *[SameFileName] with no file suffix. The asterisk before the name means that the file needs to be saved from its temporary state.
Go to the File>Save menu command, where you can either save your new file over the old one, or give it a new name and have both the suspect original file and a new, hopefully better redefined [SameFileName+2].indd file.
Try and package it again, and see what happens.
If it doesn't work, I'd then start looking for what may be a corrupted element within the file. But this trick works in the large majority of cases without extra effort on your part. So I'd start with this trick and see how it works.