If you receive an error for the throughput section in https://test.mashme.io, it is usually because your bandwidth is not big enough, or it is currently over-utilised.
The recommended network speed is 6Mbps down / 2.5Mbps up.
Mashme.io will run with a bare minimum of 300kps per user, but at the lower speeds you should expect a lower quality of signal.
To test your bandwidth:
Step 1: Run a Speed test from: https://www.speedtest.net and check that it meets the recommended speed.