Warning - Orphan Block File(s) Audacity 2.0.6


When I open my project to work again on it, a window <Warning - Orphan Block Files> pop. It explains <Project check of <Marie-Pierre-Sound-Project_data> folder found 46 orphan block files. These files are unused by this project, but might belong to other projects. They are doing no harm and are small.> And I have options to choose:

  • Continue without deleting; ignore the extra files this session
  • Close project immediately with no further changes
  • Delete orphan files (permanent immediately)

Which option should I use ?
Why Audacity is asking me that?
Can I avoid that Warning Window?

Note: this is an Audicaty program installed on university computer lab.
Thank you very much to help me.

It is safest to “continue without deleting”.

We can’t tell you exactly, unless the project crashed - did it appear to close normally last time?

It would happen if that project is a copy you made using Finder while the original project was still open. It is dangerous to make copies of projects manually using a file manager application. We strongly recommend using File > Save Project As… (see below) to make copies of projects.

It could possibly happen if when you closed the project, Audacity failed to remove AU files which were meant for Undo and Redo in that session. That should not happen.

Very rarely, if you have multiple Audacity projects open at the same time, Audacity might wrongly move AU files between different projects. Did you have more than one project open?

You will see that window each time you open the project, unless you choose the option to delete the orphans immediately. However as an alternative, you could do File > Save Project As… and choose another project name. This will close the project that contains the orphan files then create a copy of that project without orphan files.

You could then see if the “saved as” project plays correctly. If so, you could then delete the project that has the orphan files if you are sure those orphan files are not part of your project and not part of someone else’s project. One way to find that out would be to do a search inside AUP files for some of the file names listed in the Audacity log as orphan files.


I thank you a lot Gale for your information.

When it happend, I had just one project openned. The program did not crashed, it seemed to play normally. When I asked Audacity to ‘continue without deleting’, the program runned properly as well, and I could save it many times and it still worked.

However, I would have some other tips to ask you about saving audacity project.

I am teaching this program in a University Lab.

Students are going to create a project in Audacity and work on it. I want them to save their project proprely to be able to come back another day to work on it, on a different computer.

What would you suggest me as a procedure to save their project?

I usually work from the desktop, saving my project their in one specific folder (Audacity Project and audacity data folder). Then I copy this folder on a USB key or an external hard disk. When I come back, I copy again my folder on the computer desktop and I open it again in Audacity it. Is it a good way to proceed?

Many thanks for your help! I love Audacity! I really would like to teach it to my students!

I mentioned this in my last reply. If you do the copy in Finder while the project is still open, this is the cause of the orphan block files, because Audacity still has AU files that are not needed for the current state of the project, but are needed if you Undo or Redo.

So, close the project (File > Close) before you copy. Even better, insert the USB stick and do File > Save Project As… to the USB stick in Audacity. You then have the project that is on the USB stick in the Audacity project window, and you can File > Close and unmount the stick.

If the project takes many hours of work, it is a good idea to export WAV files from time to time as a backup, and/or to use File > Save Project As… to save different copies of the project as you reach each stage in its development. Add the date and time in the file name, separated by underscores such as “mysong_12oct14_23_13.aup”. Then if something goes wrong, you can open the most recent project or the most recent WAV you exported.

Also, scan the USB stick or drive regularly for viruses. If you were on Windows, you would want to consider turning auto play off on the drive, because if autoplay is on, any executable viruses would run automatically when you connect the stick or drive. As far as I know there is no USB autorun on Mac, but if you connect to a Windows machine, you should consider it.


I thank you a lot. I’ll do your method.

I tried the ‘save as’ method and it works!

Thank you.