APK emulator installation: Could Not Launch Appium Inspector

Hi all,

I failed trying to install our app on the ADT emulator, using Appium.app 1.5.2 on Mac mit OS X 10.11.4 on a system newly installed.

Environment variables set via bash_profile are:
export ANDROID_HOME=/Users/XXX/Documents/ADT/adt-bundle-mac/sdk
export ANT_HOME=/Users/XXX/Documents/Appium/ANT
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_91.jdk/Contents/Home
export M2HOME=/Users/XXX/Documents/Appium/MAVEN
export M2=/Users/XXX/Documents/Appium/MAVEN/bin

export PATH=$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools:$ANDROID_HOME/buil$

Application versions were approved for:
Android Debug Bridge version 1.0.35
Android Asset Packaging Tool, v0.2-2756797
Apache Ant™ version 1.9.7 compiled on April 9 2016
Java™ SE Runtime Environment (build 1.8.0_91-b14)
Apache Maven 3.3.9
Appium app is configured to use an application within /download

All AVDs were defined using Eclipse with ADT 23.0.2 Package.
When I start appium.app, appium doctor found no error(s), the AVD gets started as requested, APK “Appium Settings” gets installed, but it fails to install my APK automatically:

“Could Not Launch Appium Inspector”
“Could not start a new session”
“Be sure the Appium server is running with an application opened by using the “App Path” parameter in Appium.app (along with package and activity for Android) or by connecting with selenium client and supplying this in the desired capabilities object.”

But the manual installation via console succeeds, using the same path and apk as defined for appium. Any suggestions to solve this issue ?