same here, i updated the emulator to 29.3.2 (on B4A 9.50) and now i get a blank error message wen trying to start a a AVD.
Steps i tried:
1.) delete the .android folder = all my old AVD´s are gone, made a new one, again blank error message
2.) manually update SDK manager to 3.60 = no change, blank error message
3.) create new AVD = blank error message
i got it back working with a older version, steps to solve it for me:
1.) delete all in here: C:\Android\B4AEmulator\
2.) replace 29.3.2 emulator here: C:\Android\emulator with the Version 29.0.11 (thanks to wizard699 for the links above!!!)
3.) create new AVD -> runs
If you're using Android Studio, make updates first in B4A and then through Studio. In case of error, delete the c: \ Users \ <username> \ .android \ avd folder. Then delete and recreate the emulator via B4A. Do not manually delete anything in the B4AEmulator folder.