A file upload can stall because the file is too large, the format is unsupported, the name contains unusual characters, the connection changes, or a browser control blocks the request.
Short answer: Make a safe copy, shorten the filename, confirm the format and size, then retry once in a private window on a stable connection.
Check the likely cause first
- Confirm that the file opens locally and is not still syncing from cloud storage.
- Try a small plain-text or PDF test file to separate account problems from a single damaged file.
- Check whether a VPN, corporate filter or browser extension is interrupting uploads.
Fix it in the safest order
- Save a local copy and remove passwords or confidential data not needed for the task.
- Rename the copy with simple letters and numbers, then export it to a commonly supported format.
- Reconnect to reliable Wi-Fi and keep the browser tab active while the upload finishes.
- If the small test succeeds, split the original into logical sections rather than repeatedly uploading the same large file.
Change one thing at a time and retest. That makes it easier to identify the cause and undo a setting if the result is worse.
How to confirm the fix
The attachment should show a completed state and the assistant should be able to identify a harmless test detail from it. Delete test uploads you no longer need.
What not to do
- Do not use public file-converter sites for confidential documents.
- Do not disable device security or upload the same file from many tabs.
When to contact support
If every supported file stalls across devices, record the file type and approximate size and contact official support without attaching sensitive content.
For more step-by-step help, browse the PHWhy topic hubs or use the site search for the exact error message.
