Microsoft offers special .NET package for modernization of pages in SharePoint Online Microsoft Blog: Modernize your SharePoint Pages . This package relies on special file “webpartmapping.xml” for mapping of web parts. This file must be placed next to your executable. When running in development environment, all works fine. However, when deployed on client machine, there appears error like follows “Access to the path ‘C:Program Files (x86)MyAppwebpartmapping.xml’ is denied”. How to specify custom location for this file in user folder to avoid such error?