on android 6.0.1 I am getting this error when trying to use run-as.
⋊> ~ adb shell 14:29:01
shell
I was working from Delphi 10.1 berlin. I was presented with the same problem and my solution was to configure the sdk to the previous version. I was using Android SDK 25.2.5.32bit and downgraded to android SDK 24.3.3 32 bit. To configure:
Tools->Environment Options -> SDK Manager
Then, add the necessary sdk, in this case android SDK 24.3.3 32 bit.