Can't package files

[colinm72980276]

here is the message i keep getting. "This document contains links/URLs that are not accessible. Please check your network connectivity or the original source of content"

additionally, when i open files all the photos show up as a bunch of vertical lines.

[Eugene Tyson]

Sounds like they are not linking correctly or have become corrupt.

Have you checked the links panel to see if the links are broken?

Are the files stored on an external drive or a folder/drive that's linked to a Cloud service?

First thing I'd try is

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.