Xmind for Android only supports a mobile phone or tablet with the system of Android 8.0 and later version.
If you cannot install Xmind for Android on your phone, please uninstall the old version of Xmind for Android on your phone and then reinstall the application from mobile application store.
If it cannot work, please contact our Support Center (xmind-android@xmind.app ) with a screenshot of the error message.