Android Question Error : Application not installed

[PakoT52]

Hi, I have a problem , when I debug my application, clicking install in the device, exit "Application not installed". I tried with more than one application but nothing works. The logs are clean, with no mistakes in phone and you can install applications from unknown sources. How do I resolve? .
Ps: Sorry for my bad english.

 

[Erel]

This can happen if there is already an installed application with the same package name, signed with a different key. Try to first uninstall the app from the device.

 

[PakoT52]

Thank you .