Hi guys! I wonder if you could help me about this: i recorded a cover on my old laptop and then i wanted to transfer the project file on my new one for tweaking; i have transferred both the data folder and the .aup file and yes,they are in the same directory but just the same the project opens with mute tracks, i don’t know why it can’t find the data files even if they are in the same directory! 
what one has to do more than this?
Audacity Projects will not (as a rule) open upstream. If you create a show in Audacity 2.1.0, it will probably not open in Audacity 1.3.8. I expect the other way to work. Audacity 2.1.2 should open anything.
http://www.fosshub.com/Audacity.html/audacity-win-2.1.2.exe
Koz
actually both pc have windows 10 and audacity 2.1.1
The show opens without complaint, but the blue waves are flat and silent?
Protect the original by moving the AUP and the _DATA folder Somewhere Else. Maybe a thumb drive?
Now push the show back to the original computer. Still blank?
Which virus protection do you have? One of the advances in 2.1.2 is to make it less likely for overly aggressive virus protection software to destroy Audacity’s tiny project sound snippets as “Evil Foreign Invaders”.
Koz
if i remember well the first time i tried to open it it told something about orphaned files,you know the popup window asking you three actions,but now it doesn’t appear anymore
And what happened when you tried to open the possibly damaged show on the original computer?
Koz
it is just a copy, if i open the original on the pc on wich i recorded it works of course
Projects created in 2.x.x Audacity versions will open in 1.3.x versions and vice-versa.
Projects created in 1.3.x and 2.x.x Audacity versions will not open in 1.2.x versions.
Projects created in 1.2.x Audacity versions will open in 1.3.x and 2.x.x versions with a warning that you should back up the project in case Audacity fails to open it.
If you create a project in latest Audacity and open it in a previous Audacity, some data that is stored in the project in the latest version but not in the previous version would go back to default. For example, a less tall than normal track might show as default height in the previous version.
Gale
Attach the AUP file. Please see here for how to attach files: https://forum.audacityteam.org/t/how-to-attach-files-to-forum-posts/24026/1
Also please attach the log from Help > Show Log… when you try to open the project on the other computer.
Transferring a project to another computer should work if the AUP file and _data folder are together, still named the same, and if the project contains imported WAV or AIFF files, those files were copied into the project.
Gale
if the project contains imported WAV or AIFF files, those files were copied into the project.
That sounds more and more like this problem. Audacity has a very fast and efficient mode where it doesn’t make personal copies of the music, but just points to existing music when it’s needed.
All’s right with the world until the first time you move a project and forget to take all the separate, external sound files with you.
Koz