CommandInvokationFailure: Unable to list target platforms when using Android SDK > 25.2.5

This happens for both Windows and OSX, if the JAVA_HOME environment variable is not set.

Repro steps:

Install an Unity version with the Dowload asistant. Pick Editor and Android Tools
Ensure you have JDK 1.8. There is an issue with building with JDK 1.9 anyway
Navigate to Preferences->External Tools-> Android->download
this will thake you to ASndroid Studio. Download Android Studio
Chose to install the latest SDK, (26) or 25..
After instalation, go to Preferences->External Tools-> Android and chose the location where Android Studio installs the SDK.
The default is: C:\Users\[yourusername]\AppData\Local\Android\sdk

Try to build
The error you get:

-----------No.1----------------
Error:Invalid command android
UnityEditor.HostView:OnGUI()
-----------No.2------------------------
CommandInvokationFailure: Unable to list target platforms. Please make sure the android sdk path is correct. See the Console for more details.
C:/Program Files/Java/jdk1.8.0_121\bin\java.exe -Xmx2048M -Dcom.android.sdkmanager.toolsdir="C:/Users/JG/AppData/Local/Android/Sdk\tools" -Dfile.encoding=UTF8 -jar "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar" -

stderr[
Error:Invalid command android
]
stdout[

]
UnityEditor.Android.Command.Run (System.Diagnostics.ProcessStartInfo psi, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
UnityEditor.Android.AndroidSDKTools.RunCommandInternal (System.String javaExe, System.String sdkToolsDir, System.String[] sdkToolCommand, Int32 memoryMB, System.String workingdir, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
UnityEditor.Android.AndroidSDKTools.RunCommandSafe (System.String javaExe, System.String sdkToolsDir, System.String[] sdkToolCommand, Int32 memoryMB, System.String workingdir, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
UnityEditor.HostView:OnGUI()
-------------No.3-------------------------------
CommandInvokationFailure: Unable to list target platforms. Please make sure the android sdk path is correct. See the Console for more details.
C:/Program Files/Java/jdk1.8.0_121\bin\java.exe -Xmx2048M -Dcom.android.sdkmanager.toolsdir="C:/Users/JG/AppData/Local/Android/Sdk\tools" -Dfile.encoding=UTF8 -jar "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar" -

stderr[
Error:Invalid command android
]
stdout[

]
UnityEditor.Android.Command.Run (System.Diagnostics.ProcessStartInfo psi, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
UnityEditor.Android.AndroidSDKTools.RunCommandInternal (System.String javaExe, System.String sdkToolsDir, System.String[] sdkToolCommand, Int32 memoryMB, System.String workingdir, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
UnityEditor.Android.AndroidSDKTools.RunCommandSafe (System.String javaExe, System.String sdkToolsDir, System.String[] sdkToolCommand, Int32 memoryMB, System.String workingdir, UnityEditor.Android.WaitingForProcessToExit waitingForProcessToExit, System.String errorMsg)
UnityEditor.HostView:OnGUI()
--------------No.4---------------------------------
Error building Player: CommandInvokationFailure: Unable to list target platforms. Please make sure the android sdk path is correct. See the Console for more details.
C:/Program Files/Java/jdk1.8.0_121\bin\java.exe -Xmx2048M -Dcom.android.sdkmanager.toolsdir="C:/Users/JG/AppData/Local/Android/Sdk\tools" -Dfile.encoding=UTF8 -jar "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar" -

stderr[
Error:Invalid command android
]
stdout[

]

Reproduced with:
2017.2f3, 2017.3b5 and b6, 2018.1a1
But users have had this issues with 5.4 and 5.6 too...
http://answers.unity3d.com/questions/1323731/unable-to-list-target-platforms-please-make-sure-t.html

License type: Pro