I lost an app that was installed and tried to reinstall but keep getting error 24. I have cleared cache and data in google play store but still cannot install the app
Force stop Google Services, force stop Google Play, clear the data and cache in Play, then clear the data and cache in Google services. Then Play should work. (If it still says "App not installed", it was never uninstalled. Install Link2SD and see if you can find it to uninstall.)