Is it possible to run applications in Windows Phone 10 in compatability mode like you can on the desktop? I have an application that runs on Windows Phone 8.1 but users have problems when running in Windows 10 mobile.
The underlying problem is outlined here Phonegap IndexedDb not commiting data in Windows Phone 10 on larger databases but I was wondering if a fix would be availble in the settings somewhere.
There is no such concept like "Compatibility Mode" in Windows 10 Mobile. There are different emulators and devices available. Each device and emulator can run particular version of Windows Phone/mobile OS. Windows Phone provides with backward compatibility so you can run Windows Phone 8.1 app on Windows 10 mobile and test that functionality which is misbehaving or not working.