I installed studio pro.. but i unable to open APP in the application

SharpSvn.SvnSystemException: Can't hide directory 'C:\Users\Dell\Documents\Mendix\SLA Task-main_4\.svn' ---> SharpSvn.SvnSystemException: Can't set attributes of file 'C:\Users\Dell\Documents\Mendix\SLA Task-main_4\.svn': Access is denied.      --- End of inner exception stack trace ---    at SharpSvn.SvnClientArgs.HandleResult(SvnClientContext client, SvnException error, Object targets) in d:\bb\sharpsvn-v1.900x\v40\src\sharpsvn\svnclientargs.cpp:line 78    at SharpSvn.SvnClient.CheckOut(SvnUriTarget url, String path, SvnCheckOutArgs args, SvnUpdateResult& result) in d:\bb\sharpsvn-v1.900x\v40\src\sharpsvn\commands\checkout.cpp:line 62    at SharpSvn.SvnClient.CheckOut(SvnUriTarget url, String path) in d:\bb\sharpsvn-v1.900x\v40\src\sharpsvn\commands\checkout.cpp:line 35    at Mendix.Modeler.VersionControl.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 91   this is the error iam getting
1 answers

The source of the error message is:
'C:\Users\Dell\Documents\Mendix\SLA Task-main_4\.svn': Access is denied. 

So you have a permission problem with windows. 
This can e.g. occur when you are not working with the user Dell or have created the project with another user.