I've just made some changes to an app and recompiled.
For testing I then forward the build links to my Android phone as I have always done.
Once downloaded the APK files is not being recognised as an installation file and fails to install.
Previously APK files have an Android symbol alongside the download. These latest have a black icon.
Sometimes Android has trouble doing side-load installs, especially if you have multiple apps with the same App ID or version codes that are out of sequence. I recommend you uninstall the other side-loaded apps and try again, there may be such a conflict with your previously side-loaded apps. Or, you may be attempting to install a ZIP file (when you build with Crosswalk you are given a ZIP file that contains two APK files, you need to install the APK file that matches the architecture of your device, download and run the CPU-Z app or the CPU-X app to see what the CPU architecture of your Android device is). See the Crosswalk docs > https://software.intel.com/en-us/xdk/docs/lp-crosswalk < as well.
They are definately APk files. The files are opening as text files after downloading.
I'll try as you suggest and remove previous version if app but never had this issue before.