The "can't download this document because it's no longer on your phone" error on WhatsApp Web occurs when the platform attempts to pull a file from your mobile device's storage, but the file is missing, deleted, or inaccessible. Why This Error Occurs
If the document won't open on your phone either, browse your phone's internal storage: The "can't download this document because it's no
: Internal Storage > Android > media > com.whatsapp > WhatsApp > Media > WhatsApp Documents. How to Fix the Error 1
: Occasionally, the session between your PC and phone is "stale," and the browser fails to recognize the file even if it exists on the phone. How to Fix the Error 1. Open the File on Your Phone First but the file is missing
: You or a cleaning app deleted the file from your phone's "WhatsApp Documents" folder to save space.