After update Android Studio to 3.2 and solve problem with sync gradle Gradle sync failed - after update Android Studio to 3.2 - i cant install apk -
Event Log:
I resolved this problem - in my case I found in Activity Monitor on my Mac several processes of adb and kill force all processes until stayed 1 adb processe and it helped.
EDIT: try in terminal comands :
adb kill server
adb start server
It help to restart your adb, I have to do it all the time on Android Studio =(
EDIT-2: also magic way to fix:
adb install -r -t apk_debug.apk
And then just "Run app" from android studio