Hi,
I'm on Antergos Linux, Gnome 3 and Kdenlive Version 15.04.0.
When I save a project then try to re-open it I get the message that this "is not a kdenlive project file".
I have the same set up on another computer and get the same error.

Any help greatly appreciated as I can't get any work done if I can't save/reopen a project

It once happened to me too. I found out that kdenlive wasn't adding the .kdenlive extension to the name of the file. Check that out. There is a check box for that in the "save" window dialog.

Thanks,

There is no check box that I can see in the save dialogue but when I manually added the extension .kdenlive to the file, Kdenlive opened it.

Thanks for your help. It gets me around the problem for now.