Some errors occurred while installing the agent

Hello everyone,

On Mobile Screen

I click the "Enable" button (or click "Install Android Agent" icon) the error message "Some errors occurred while installing the agent" displays (Screenshot "agent.png")

I try using enable Agent manually. Use script as below:

def InstallAgent():
AgentApkPath = "C:/Program Files (x86)/SmartBear/TestComplete 12/Bin/Extensions/Android/AndroidAgent.apk";
Agent = Mobile.Device().PackageManager.GetPackageFromAPK(AgentApkPath);
Mobile.Device().PackageManager.InstallPackage(Agent);

But I receive the error when run scripts (Screenshot "manual.png")

Please support me how to enable Test Complete Agent. 

Many thanks,

Xuan Pham