When using Filerev, you might receive a message like:
1. The file was shared directly with you (read-only access)
Could Not Delete File - You have read-only permission to this file, and it cannot be removed from your Google Drive account.

or
Could Not Modify - Failed to retrieve the necessary information to remove this item.

This happens when someone shares a file with you but gives you read-only access or you have opened a publicly shared file. Since you do not have write permission to this file, Google has chosen to prevent you from making any modifications to the file.
However, there is a workaround where you can hide the file from your Google Drive account by finding it in the "shared with me" location, right-clicking the file and selecting remove. This hides the file from your account, but you technically still have access to the file. If you open the file again (by going to the direct link), it will reappear in the shared with me folder.
Pro tip: If the delete icon or delete option is disabled on a file in Google Drive, try dragging the file to the trash/bin in the sidebar. This will often let you remove the "shared with me" files that cannot be removed any other way.

2. The file is inside a shared folder
You may also see this message:
Could Not Modify – This file is part of a shared folder and cannot be removed individually.
This happens when a file is inside a shared folder. In this case, your access to the file comes from the folder, not the file itself.
Because of that, Google does not allow individual files inside the folder to be removed on their own.
What you can do
To remove these files, you need to take action on the shared folder, not the file:
- Try removing the shared folder from your Drive
- If that option is not available, ask the folder owner to change access or remove you from the folder