I could not get past the 'Connect to Wi-Fi' step, using the app on my Android phone, in Setup for my Echo Dot.
Amazon Echo customer support was of no help over e-mail. I rebooted my phone, un-installed and re-installed the Alexa app, un-plugged and re-plugged in the Echo Dot. Nothing changed.
After making sure the light ring was orange, and tapping the 'Connect to Wi-Fi' button on the Alexa app on my Samsung Galaxy S6 phone, the Setup screen would just go blank (white). After several minutes, I noticed an error had appeared at the top of the screen, that read: 'Auto Network Switch' still enabled. Unable to complete setup.
In the back of my mind, I remembered a network setting on my phone about automatically switching between WiFi and the Mobile Data networks, but I couldn't find that setting (and I spent a LONG time looking around, too!). The setting is NOT under 'Mobile Networks' (as you might expect) and it is NOT called 'Auto Network Switch' on Galaxy devices.
The setting is under Wi-Fi, then tap 'MORE' (in the upper-right) and tap 'Advanced' from the pop-up menu. On the Advanced screen, you will see a setting for 'Smart network switch'.
Apparently, in order for the Alexa app to complete setup, the 'Smart network switch' setting must be set to 'OFF'. Once I turned 'Smart network switch' OFF, I was able to easily complete setup in the Alexa app.
If you have run into this problem/error, I hope this saves you the pain I went through! I thought I was going to have to send the Dot back to Amazon!