Assuming the last changes were committed you could try to download the project again in a new folder.
If that doesn’t allow the mda to be created then please create a ticket with Mendix support, they will be able to help you further.
I also found this issue.
Cannot Create Deployment Package
and if I move my local app to other folder I cannot download app again.
I think the problem caused from SVN ?
Remark: Mendix 9.13.1
SharpSvn.SvnSystemException: Error running context: An existing connection was forcibly closed by the remote host.
at SharpSvn.SvnClientArgs.HandleResult(SvnClientContext client, SvnException error, Object targets)
at SharpSvn.SvnClient.CheckOut(SvnUriTarget url, String path, SvnCheckOutArgs args, SvnUpdateResult& result)
at SharpSvn.SvnClient.CheckOut(SvnUriTarget url, String path)
at Mendix.Modeler.VersionControl.SvnClientAdapter.CheckOut(SvnUriTarget url, String path) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.VersionControl\Svn\SvnClientAdapter.cs:line 62
at Mendix.Modeler.VersionControl.Windows.SvnConnector.Checkout(IRemoteRepository remoteRepository, IRevLine branchToCheckout, String targetProjectDirectory) in C:\Users\Autobuild\workspace\AppStudio4.0-Build\modeler\Mendix.Modeler.VersionControl.Windows\Svn\SvnConnector.cs:line 69