Troubleshooting

The app will not install or open

Windows

If SmartScreen blocks the installer, choose More info → Run anyway. The desktop build is code-signed, so this normally does not appear.

If the app installs but will not launch, try the Microsoft Store build instead — it handles its own dependencies.

macOS

If macOS refuses to open the app, allow it under System Settings → Privacy & Security, then launch it again. Make sure you moved 9xconvert into Applications rather than running it from the mounted disk image.

Linux

Check that the downloaded file is marked executable. If it is not, set the executable bit and run it again.

Android

Install through Google Play so updates arrive automatically. If the app will not start, update it and restart your device.

A conversion fails partway

1. Check free disk space. Conversion writes the output alongside the source, and large video jobs need room for both. A full disk fails mid-job.
2. Check the source file. If one file fails and others succeed, the source is likely damaged or in an unexpected format. Try playing it first.
3. Try one file on its own. If a single file converts but the batch does not, the problem is one item in the queue rather than the app.

New conversions stop starting after a few files

A free account converts five files a day, so a selection can start successfully and then stop part-way with nothing wrong at the source. Check User Account for the current plan, and see Free and Pro. Files already converted are unaffected, and the allowance returns the next day.

A free account also caps how many files a single import adds, so a folder drop can stage fewer files than the folder holds. The staging list on Home shows what was accepted.

UID validation fails

• Paste the UID again without surrounding spaces. It has the shape 1234-5678-9012, which the app shows under the entry field.
• Confirm the device is online. Conversion works offline, but verifying an account does not.
• If a device-limit message appears, the UID is valid and already in use elsewhere: a free account covers one device and Pro covers three. Open User Account → Manage License to review what is connected.

Read Your 123sudo UID before switching accounts. Creating a new UID creates a separate account; it does not move the licence from the saved UID.

I cannot find the file I converted

Open Conversions → Completed and use the row's Folder action, which reveals the file where it was actually written rather than where the default points now. The default destination is Settings → Conversions → Location, and it may have been changed since the conversion ran.

Clearing an entry from Completed removes the history record, not the file on disk.

The file is rejected, or the conversion produces nothing

1. Confirm the file opens in another application — a partially downloaded or truncated file often fails here first.
2. Check the input is really the format its extension claims. A .mp4 that is actually something else will not convert.
3. Close any application that currently has the file open, then retry.
4. Try Convert to a common format first, then run the operation you wanted on the result. A container the tool cannot read directly is often fine once re-encoded.

If one file in a selection fails and the rest succeed, the problem is that file rather than the app.

Conversion is slower than expected

Processing speed depends on your own hardware, since nothing runs on a server. Large 4K video, heavy compression, and long batches are all CPU and GPU bound.

Closing other demanding applications while a large batch runs makes a noticeable difference. On mobile, conversion is bound by your phone's chip and will be slower than a desktop for the same file.

A download-to-convert link does not work

The download step is the only part that needs the network:

• Confirm you have a working connection — the conversion half works offline, but fetching the media does not.
• Confirm the link is publicly reachable. Content behind a login or region lock may not be retrievable.
• If the download completes but the conversion does not start, convert the downloaded file directly to isolate which half failed.

Output quality is not what you expected

Compression settings trade size against quality. If an export looks worse than the source, revisit the compression level and output format before assuming the conversion is at fault — re-encoding to a lossy format always loses some detail.

Nothing here helped

Reach out through support. Include your platform, the app version, the file type you were converting, and the output format you chose.