Since installing the latest update v7.8 of B4A the AVD Manager from the tools menu fails to find any configured AVDs. I can configure them in Android Studio and use them successfully in B4A but the B4A AVD manager cannot identify them. It's an annoyance more than anything. Is this a common problem?
Install all the required components in B4A SDK. Also make sure that you are up to date with Java, I think it's version _152. Is your system Intel based, if so please make sure that Intel® HAXM is installed in your system. Basically make sure that you have the newest of everything on your system including Dotnet Framework.
When installing images, make sure that you are installing Intel x86 Atom System Images.