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Why do I get "Error while opening sound device"?

This error message asks you to check the recording or playback device settings and the Audacity project sample rate. If the message mentions "recording device", it means there's a problem with your Audacity, operating system or sound device recording settings. If the message mentions "playback device", it means there is a problem with your playback settings.

Either message can suggest a problem with the drivers of the sound device, or possibly that you are asking the device to do something it cannot do. For example you will see this error if you attempt to append record to more channels than your device supports, or if you try to overdub on a device that can either record or play back but not both.

The recording device message most commonly occurs on Windows Vista, Windows 7 or Windows 8 when one of the sound device inputs is not properly enabled or otherwise cannot respond to Audacity's request to start recording.

Check Audacity Settings

It may be a good idea to try to play or record after checking or changing each of the following Audacity settings. Sometimes a project rate change is all that is needed.
  • Set the project rate bottom left of the Audacity window to the standard rate of 44100 Hz (or if your soundcard only supports a particular rate such as 48000 Hz, set the project rate to that). Help > Audio Device Info... should show the rates the device claims to support.
  • Check in Device Toolbar that the playback and recording devices are correctly and explicitly selected.
    • On Windows, don't choose "Microsoft Sound Mapper" or "Primary Sound Driver" which point to the current Windows default device; choose the required device by name. Try selecting "Windows Direct Sound" as the "Host" instead of "MME".

Check operating system settings

  • Windows: Follow the Wiki instructions for Windows XP or Windows Vista, Windows 7 or Windows 8 to configure the Windows sound settings. The key points are:
    • Ensure all available inputs are listed and enabled in the Windows Control Panel.
    • Additionally for Windows Vista, Windows 7 or Windows 8: Ensure Default Format for the playback and recording devices contains the same sample rate and number of recording channels as in Audacity.
      • Very rarely, it can help to use 16-bit or 24-bit Default Format then change the Audacity Quality Preferences to that sample format.
      • If necessary, put a checkmark in both Exclusive Mode boxes then set the "Host" in Audacity's Device Toolbar to "Windows DirectSound" and choose a project rate that your playback and recording devices support. Audacity can then request that rate directly from the sound device.
  • Mac OS X: In Finder, choose Go > Utilities > Audio MIDI Setup.app. In "Audio Devices", select in turn the required Recording and Playback devices. Set "Format" to the same sample rate, bit-depth and number of recording channels as in Audacity.
  • Linux:
While troubleshooting, ensure that Transport > Software Playthrough (on/off) is off. Only enable this option if you really need it, after you have established that Audacity is recording correctly.
  1. In the first instance, try refreshing Audacity's list of audio devices at Transport > Rescan Audio Devices then select the default option in Device Toolbar. If the error still occurs, recheck the Audacity settings.
  2. It is possible that another application may have exclusive access to the audio device. Try logging out and back in again, then re-check the Audacity settings before opening any other application that may use the audio device.
    • If pulse is an option in Device Toolbar, ensure that you have Pulse Audio Volume Control (pavucontrol) installed. If it is not installed, use your system's package manager to install it. Open Pulse Audio Volume Control and check that there is an available output device.
    • If Jack Audio System is running on the computer, ensure that it is selected as the Host in Device Toolbar.
  3. Open the system Sound Preferences and check that a recording device is available. Sound Preferences is often available through a loudspeaker icon on the Desktop, Desktop panel, or in the system Preferences menu.
  4. Open AlsaMixer (type alsamixer in a terminal window) and check the soundcard and recording device settings. To view the AlsaMixer manual, type man alsamixer in a terminal window.

Check sound device drivers and firmware

The computer's built-in sound device should usually have the latest drivers for your operating system, supplied by the motherboard or computer manufacturer. A PCI or external soundcard should usually have the latest drivers and firmware supplied by the manufacturer of the device. See Updating Sound Device Drivers on the Wiki for help with correcting driver issues.

Check PCI card or external sound device settings and connections

If you use a high-end PCI soundcard or external USB or Firewire interface, you must make the sample rate, bit-depth and number of input channels the same in all possible places. This is especially important if you are recording Multi-Track Overdubs where you play and record at the same time. Settings must match in:

  • the Audacity Project Rate
  • the track(s) in Audacity (to resample tracks to the Project Rate, select each track in turn then choose Tracks > Resample...).
  • all inputs and outputs in the operating system sound control panel or application
  • all inputs and outputs in any software or hardware control panel the sound device may have.
Make sure the device is connected properly. "Error while opening..." will occur if the device becomes disconnected during an Audacity session and you then try to play or record. Reconnect the device then choose Transport > Rescan Audio Devices.

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Why do I get "Error: not well formed (invalid token) at line x"?

This usually means that when reopening the AUP project file normally, Audacity finds an unexpected non-English, accented or control character at the line quoted in the error message. There are two main causes of this.

  • The project contains imported files whose metadata (like artist or genre) contains control characters. This mostly occurs with iTunes files on OS X where the project was created in an older version of Audacity.
  • The project was saved containing non-English or accented characters using an old ANSI build of Audacity for Windows. ANSI builds are not properly Unicode aware, so do not support non-English or accented characters.

The invalid token error can also occur if Audacity or the computer crashed. Audacity will try to recover the project from its autosave file but the crash may cause a redundant line near the end of the file that triggers the error. Very occasionally, the AUP file may become corrupted by one or more redundant lines even if there was no apparent crash.

Solution for error caused by control characters

  1. Make a copy of the AUP project file and open it in a text editor like Notepad (Windows) or TextEdit (Mac).
  2. Turn word wrap off in the menus (or in TextEdit, drag the window horizontally so that lines do not wrap).
  3. In the line indicated in the error message, look for one of these:
    • projname=
    • name=
    • value=
    • title=

    then remove all characters inside the quotation marks that follow which are not a number or an A to Z letter. You could also change those characters to a number or A to Z letter. For example, a string of control characters you would want to remove or change might start with &# followed by four numbers and a semi-colon, such as &# 0 0 1 3 ;.

  4. Save the changes to the .aup file.
  5. If you re-open the project and an error occurs at another line, repeat the steps above in the new line indicated in the error message.
Here is a real-world example of a corrupt line in the GENRE tag in a project where "Drama" and "Comedy" were incorrectly separated using the control character for a horizontal tab, also missing the closing semi-colon:

<tag name="GENRE" value="Drama &# 0 0 0 9 Comedy"/>

And the same line corrected so that the two words can be read into the project:

<tag name="GENRE" value="Drama, Comedy"/>

"Drama 0009 Comedy", though meaningless, would also enable the project to be opened correctly.
Warning icon

If you had to rename "projname" in the AUP file, rename both the AUP project file and the corresponding _data folder so that they have the same name as "projname" in the AUP file.

Solution to correct an AUP file created in an ANSI version of Audacity, preserving non-English characters

  1. Make a copy of the file
  2. Open the file in Notepad++ (a free text editor that supports UTF-8 encoding of Unicode characters)
  3. Choose Encoding > Convert to UTF-8 without BOM
  4. Save the changes to the file.

Solution to correct an autosave file that Audacity is attempting to recover from

If you have an AUP file with a token error not solvable by deleting invalid characters, try checking for and deleting any empty lines or duplicate </project> lines as per steps 4 through 7 below.
  1. Find the autosave file. It will be in an "AutoSave" folder in Audacity's folder for application data as follows:
    • Windows XP: Documents and Settings\<user name>\Application Data\Audacity
    • Windows Vista/Windows 7/Windows 8: Users\<user name>\AppData\Roaming\Audacity\
    • OS X: ~/Library/Application Support/audacity/
    • Linux: ~/.audacity-data/ .
  2. Make a copy of the autosave file as a backup and move the copy somewhere else such as your Desktop.
  3. Open the original autosave file in a text editor like Notepad (Windows) or TextEdit (Mac).
  4. Turn word wrap off in the menus (or in TextEdit, drag the window horizontally so that lines do not wrap).
  5. Go to the line indicated in the error message. If you had been recording, the last line above it will probably look like </recordingrecovery>.
  6. We need to delete the entire line. It may be a long line containing only empty spaces or it may have </project> at the end of all the spaces. Hold Shift and press Down to select the entire line before pressing Delete. Ensure this leaves you with a final line that contains only </project>. Ensure this is the only line that contains </project>.
  7. Save the changes to the file.
If none of the above helps to correct the invalid token error, you can:

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Why does the computer reboot or show a blue screen message when I launch Audacity or play or record?

This mostly affects Windows computers. It happens when your computer sound device has a bad or mismatched driver or there is a problem with a system driver that interacts with that sound device. Even if the problem occurs after updating to the latest Audacity version, it still isn't Audacity's direct fault because Audacity does not have kernel privileges to make the computer restart. Inappropriate drivers can also cause Audacity to crash during playback or recording, without necessarily crashing the computer.

The best practice is to make sure the computer's built-in sound device has the latest drivers for your operating system, supplied by the motherboard or computer manufacturer. For a PCI or external soundcard, obtain the latest drivers and firmware supplied by the manufacturer of the device. See Updating Sound Device Drivers on the Wiki for help with correcting driver issues. If playback or recording worked previously, but the sound device drivers are appropriate or cannot be changed to a version that prevents the problem, try Windows System Restore to revert the computer to a state before the problem occurred.

If necessary the exact driver or module causing a computer crash can be pinpointed on Windows by examining the memory dump made when the crash occurred. You can find the dump by right-clicking over My Computer or Computer > Properties, then click the "Advanced" link or tab, and under "Startup and Recovery", choose "Settings...". WhoCrashed is a Windows tool that makes it easy to identify the driver or module at fault.

If your best available soundcard drivers prove to be incompatible with current Audacity, we may not be able to take any direct action, but do let us know:

  • the exact make and model number of the sound device
  • the exact driver and firmware model numbers
  • the exact operating system you are using, including the Service Pack if you are on Windows.

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Mac OS X: Why do I see "Critical Nyquist files cannot be found"?

This error occurs on Mac OS X if Audacity is run directly from the downloaded DMG file. If you do this you also won't be able to save or export files without changing the directory you are saving or exporting to.

Here is the correct way to install Audacity from the DMG file obtainable from http://audacity.sourceforge.net/download/mac .

  1. Double-click the downloaded DMG to mount it.
  2. Copy the "Audacity" folder from the newly mounted DMG to /Applications (or any other location of your choosing).
  3. Eject the DMG at bottom left of Finder, then launch Audacity.app from the "Audacity" folder that you copied.

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"I found a bug!" or "Feature X is not good enough or is missing!" now what?


The most important things when reporting a bug are to be as specific as possible and check first in the Release Notes if we already know about the problem.

If the bug is not known about, please give us enough information that we can reproduce the bug ourselves on the correct operating system. Otherwise it's unlikely that we'll be able to fix it.

Warning icon Please include the following essential information in your report:
  • Your exact three-section version number of Audacity (for example, 2.0.0) - you can check this at Help > About Audacity or Audacity > About Audacity on a Mac computer
  • The exact operating system you are using (for example, Windows 7 Service Pack 1, Mac OS X 10.6.8, Linux Ubuntu 11.10)
  • Any other information about your computer and its audio connections that might be relevant (for example, 2 GB RAM, 2.2 GHz, M-Audio Fast Track USB interface).

If you can make the problem happen consistently, tell us the exact sequence of events, step-by-step from launch of Audacity that causes the bug to occur.

If you see an error message, be sure to send us the exact text of the error message, or attach an image. If you are on OS X or Linux a crash report is useful too.

When you have your bug report ready, please email our feedback address.

Feature Requests

You can also send your ideas for new or improved features to our feedback address. Again, be as specific as possible, and feel free to suggest your preferred way of achieving the functionality you desire. If you are a regular visitor to our Forum, you can instead post your suggestions on the Adding Features to Audacity board.

If you are a C++ programmer, you can send us a patch for the bug fix or new feature.

Thanks for all your reports, suggestions and patches! All of these help us make Audacity better.

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