Any person who can edit my document cannot see or open the files I add – Grant Access to Files

This is a security setting that you can change in the Settings tab.

Please select the appropiate files access permissions before adding the files to your document for others to see/edit/open.

screenshot docs.google.com 2023.02.14 16 15 18

 

If you added the files and you want to change the permissions, please open the Folder Tools* sidebar and use one of the tools for changing the access type in bulk.

filedrop tools menu

Here, select the Folder Tools menu.

Or in the Google Sheets top menu, Extensions -> FileDrop->Folder Tools.

filedrop change files permission

You can also do this manually by going to Google Drive, selecting the files you want to share, and changing the share settings for the files.

*paid tool.