I think this is an error caused by permissions, First of all, shouldn't the App be under wwwroot? You can try to move your "OurApp" to the wwwroot folder and try again. Then check if the IIS_IUSRS has permission for the wwwroot folder. By default, the IIS user does not have write permissions for the wwwroot folder.
1.Open File Explorer and go to C:/inetpub/
2.Right click on wwwroot and click on "Properties"
3.Go to the Security tab and click "Edit..." to edit permissions
4.Find and select the IIS user. In my case, it was called IIS_IUSRS ([server name]IIS_IUSRS).
5.Select the "Allow" checkbox for all permissions.
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