You're trying to upload multiple files larger than 4 GB (e.g., very large video files), which isn't currently supported.
You can paste 2LBY9VSM, F9D46S3Z, and BUI9YK2E into the search bar in All Fields & Tags mode to find the attachments in question. You'll need to delete them and empty the trash. If you don't have another copy, you can Show File and move the file somewhere else on your computer and then add it back as a linked-file attachment.
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You can paste 2LBY9VSM, F9D46S3Z, and BUI9YK2E into the search bar in All Fields & Tags mode to find the attachments in question. You'll need to delete them and empty the trash. If you don't have another copy, you can Show File and move the file somewhere else on your computer and then add it back as a linked-file attachment.