Hello i have been trying to open an AUP file for a while now and it won’t open no matter what I do or found any solution online. I have not moved the files and I am getting a prompt to use the open file command but that’s what I have been doing the whole time. all my other files work and everything else i working fine.
attached is a screen shot of the command it is giving me
Thank you for your help
Stefan
I suspect that the AUP file may be corrupt. If you could attach the AUP file to your reply we can take a look and check. See here for how to attach a file to your forum post: https://forum.audacityteam.org/t/how-to-attach-files-to-forum-posts/24026/1
dear friend, i have the same problem, have you found the solution? this command is also appear when i tried to open one of my (unfortunately the most important) project. please help 
An Audacity Project Manager, AUP file, is a text file and will open in a text editor. Open yours in your editor (don’t save anything) and see if it’s healthy.
I expect it to look something like this. This is a cleaned up version of a real project.
If it’s blank, or contains nothing but lines of NUL NUL NUL…, then you have a damaged project. Let us know which way it goes, and what kind of project it was. If it was a raw, first-pass, mono performance, there might be a way to rescue it.
Koz
If the error message says “Error Importing” then you are trying to import the file using File > Import > Audio.
Try File > Open instead.
– Bill
I’ve been informed that the error message you received (“Error Importing”) can also occur when opening a damaged Audacity project (AUP) file. Take a look inside the AUP file as Koz suggests.
– Bill