Hello,
I use Audacity v 2.1.1 for Windows 8.1 on a laptop.
I have recorded 1 hour of audio but I have not closed audacity before saving project. I have closed the laptop and go out but the battery unplugged. 
When I try to open the .aup file, audacity send a message “use the file > open command to open project”.
I suppose audacity cannot open file because the end of file character is missing.
How to restore this file and my audio project ?
Thanks
BR
The AUP file is text. You can open it in a text editor and read it.
The AUP is the Audacity instructions how to put your show together from the stuff in the _DATA folder of the same name. The _DATA folder has a fragmented version of the show.
The AUP file is written last when you save a Project. Is it full of code when you open it in Notepad?
Koz
Thank you for your answer.
The .AUP file seems empty or filled by blanks when I open it with Notepad. However, its size is 136 Ko.
Is it possible to create this file manually ?
Else, how to organize manually .AU files ?
Thanks
We can’t tell you unless you attach the file, but from your description the AUP file is just NULL’s. It can happen if you shut down the computer before waiting for the project to completely save. The AUP file is written last, after Audacity finishes moving the AU files from the temporary folder to the _data folder for the project.
If you never edited the recording, you can make fresh WAV files from the AU files in the project’s _data folder. See Recovering crashes manually.
Gale