glMapBufferOES fails with GL_INVALID_VALUE in GLES 3.0 Emulator

I have an OpenGL engine set up, and have added OpenGL ES support to it recently. Currently I am targeting android, and in an effort to speed up debugging I have added OpenGL ES support to the windows side of things using the MALI GLES 3.0 Emulator.

I am using the GL_OES_mapbuffer extension if it is available for sprite rendering, falling back to glBufferData if it isn't. This works on both my test phone, which supports the extension, and the android emulator, which doesn't. However running this on my main computer results in the call to glMapBufferOES to return null and calling glGetError returns GL_INVALID_VALUE. I find this strange, since glMapBuffer shouldn't even return GL_INVALID_VALUE, so I assume this is a bug.

I am calling glMapBufferOES with these arguments, it should be valid for OpenGL ES. glMapBufferOES(GL_ARRAY_BUFFER, GL_WRITE_ONLY);

Does anyone have any idea why this would be happening, any help would be appreciated.