Many users were complaining about Lumia-specific apps not updating from the store in Windows 10 Mobile. Today, Microsoft shared the info on what is happening. Lumia apps are not updating (and showing various error codes) when trying to install or update on a device that has been upgraded to Windows 10 Mobile because these Lumia-specific apps have not yet been ported into the Windows 10 store. Microsoft also confirmed that at this time there is no workaround for this issue. Until these apps are ported to the Win10 Store, users will not be able to reinstall or update these apps. Microsoft is yet to complete the specific changes for Windows 10 store that before these apps can be ported over. However, they have assured that they are working on it and it will be released in the future builds.