Troubleshooting

If you're having trouble, work through the relevant section below. If your issue isn't listed here, contact support@stemdirector.com with your system info and a description of the problem.

Audio dropout or crackle

Dropout is almost always caused by one of three things: buffer size too small, CPU overload, or storage speed.

1. Increase the buffer size

Open Preferences → Audio and increase the buffer size to 512 or 1024 samples. This increases latency slightly but eliminates most dropout caused by CPU spikes.

For live performance, a 512-sample buffer at 48 kHz gives ~10 ms of latency — imperceptible when playing to tracks.

2. Check CPU load

The CPU meter in the main window shows real-time load. If it's consistently above 80% during playback:

Close other applications running on the machine
Disable Wi-Fi (active Wi-Fi scanning can cause audio interrupts)
On macOS, disable Spotlight indexing during performance: sudo mdutil -a -i off
On Windows, set the power plan to High Performance

3. Check storage speed

Open your system's disk activity monitor during playback. If disk reads are maxing out, your stems may not be on an SSD. Stem Director requires SSD storage — HDDs are not supported for stem playback.

4. Check the ASIO driver (Windows only)

Open your audio interface's ASIO control panel and confirm:

The sample rate matches Stem Director's configured rate (default 48 kHz)
The ASIO buffer size matches what Stem Director is set to

A mismatch between the ASIO driver buffer and Stem Director's buffer will cause consistent dropout.

MIDI device not detected

Check device recognition

Open Preferences → MIDI and look for your device in the input device list. If it's not there:

Disconnect and reconnect the USB cable
On macOS, open Audio MIDI Setup (in /Applications/Utilities) — if the device doesn't appear there, it's not recognised by the OS
On Windows, open Device Manager and check for any MIDI devices with error icons

Check the MIDI driver

Some MIDI controllers require a specific driver installed before they appear as MIDI devices. Check the manufacturer's website for macOS/Windows driver downloads.

Bluetooth MIDI (macOS only)

For Bluetooth MIDI devices:

Open Audio MIDI Setup → Window → Bluetooth Configuration
Pair the device here first
Then enable it in Stem Director's MIDI preferences

Bluetooth MIDI is not supported on Windows.

MIDI messages arriving but not triggering actions

If the MIDI device is detected but actions aren't firing:

Check that the device is enabled (checkbox ticked) in MIDI preferences
Verify the MIDI channel matches — if the mapping is set to channel 1 but the device sends on channel 10, it won't trigger
Use MIDI Monitor (free macOS app) or MIDI-OX (free Windows app) to confirm what messages your controller is actually sending

Licence activation fails

Check internet connectivity

Licence activation requires an outbound HTTPS connection to api.stemdirector.com. Confirm your machine can reach this address:

# macOS / Windows (in Terminal / Command Prompt)
curl https://api.stemdirector.com/health

If this fails, check your firewall and proxy settings. On corporate networks, you may need to whitelist *.stemdirector.com.

Licence already in use

If you see "Licence already activated on another machine":

Sign in to your portal account
Go to Licences → Manage Devices
Deauthorise the old machine
Return to Stem Director and activate again

If you can't access the portal or the old machine is no longer available, contact support@stemdirector.com for a manual deactivation.

Wrong email or password

Licence activation uses your Stem Director portal account credentials. If you're unsure of your password, use Forgot Password to reset it.

Show file won't open

Version mismatch

If you see "Show file was created with a newer version of Stem Director":

Check for updates: Help → Check for Updates
Install the latest version
Try opening the file again

Show files from older versions always open in newer versions. Downgrading to an older version to open a newer show file is not supported.

Stems can't be found

If Stem Director opens the show file but shows missing stems (red indicators):

Click the missing stem indicator
Click Locate File and browse to the new location
If all stems moved to the same folder, click Locate Folder — Stem Director will re-link all missing stems in one step

This happens when you move your stem files to a different drive or folder. The show file stores relative paths — if stems and the show file move together (same relative structure), they will always find each other.

Video won't play

See Video Sync — Troubleshooting for video-specific issues.

Redundancy won't connect

IP addressing

Confirm both machines have static IP addresses on the same subnet with no firewall between them:

# On each machine — should reach the other
ping 192.168.10.1   # from secondary
ping 192.168.10.2   # from primary

Firewall

Stem Director uses TCP port 7700 (configurable) for redundancy sync. Ensure this port is open in your OS firewall:

macOS: System Settings → Network → Firewall → Options → add Stem Director as allowed incoming connection

Windows: Windows Defender Firewall → Allow an app → Stem Director (or add port rule for TCP 7700 inbound)

Show file mismatch

Both machines must have the same show file. If the secondary refuses to sync, compare the show file modification dates. Copy the primary's version to the secondary and try again.

Still stuck?

Contact support@stemdirector.com with:

Your OS version and Stem Director version number (Help → About)
Your audio interface make and model
A brief description of what you were doing when the issue occurred
The contents of the log file:
- macOS: ~/Library/Application Support/StemDirector/logs/latest.log
- Windows: %APPDATA%\StemDirector\logs\latest.log