All data will be deleted, including whatever bug prevents the app from properly working. After selecting the app, select advanced options. In the system sub-menu, navigate to Apps and Features Search for the app in question. Microsoft is making it easier and safer to use Windows store apps as opposed to legacy apps on Windows 10, and this new tool is just another way of showing it. What this does is reset all settings and data in a given app so the app is reverted to the state it was when it was initially installed from the store - flixing buggy apps without forcing an uninstall.

If it was a built-in app, the user would mist likely have to find a workaround or hope a store update flushed out the junk data interfering with the system. Whatever the issue, when it arose in Windows 10 version and below, the only recourse was to uninstall and reinstall the app in question. Perhaps its an issue with the Store app, preventing you from downloading and updating any of your already installed apps, or the mail app is crashing at launch for no obvious reason, or photos is playing hide and seek with your very important selfies.

Windows 10 mail app crashing