An error message & Blank Project

Hello there,
I am hoping someone can help with this issue regarding Audacity. A user has been working on a project for a couple of weeks & everything seemed to be fine up until now. When opening the project there is no audio, the screen is just black as if audio was never created in the first place. An error message also pops up when trying to open the project, ‘This project is already opened in another window’ even though it is not. When I tested it by creating an audio & saving it on the same project, the test audio saved. Is it an issue that the user was not correctly saving the project or is this something deeper. This issue has only occurred today so the project with the correct audio has opened successfully before which is leading me to ask for support on this issue .

There is another copy of Audacity running. You could use a system command to close it, but I don’t know what it will do to the project file if Audacity is closed unexpectedly.

I hope others here have more insight.