if your neato drops at "registering in neato servers", then it's probably your wifi
First of all, I wanted to post as answer to another thread, but couldn't find it. Nevertheless, I think this is important so here we go.
Symptom: connected to wifi just fine. At connecting to the Internet, it hangs for a while then quickly green check that, but almost immediately red cross the following step (registering to server).
I thought it was because of their server. Until yesterday.
Here's how I got it running (assuming the neato is in discovering mode) 1. Turn off your 5Ghz band. Restart router. Allow only 2.4Ghz. 2. Open Neato app. Click until there's the screen "select the wifi access point". 3. Minimize the Neato app. 4. Go to your phone settings, manually connect to Neato wifi. Wait until it's connected and check the network quality and all the stuff. 5. Come back to Neato app. At this point it should show you a list of wifi SSID to connect to. 6. Choose your SSID and connect to it. 7. Should be fine.
The most important part for me was step 1. I had a dedicated SSID at 2.4GHz for neato, but also several other SSID running both at 5Ghz and 2.4Ghz. I didn't think it was a problem, until yesterday. You need to turn off the 5Ghz radio of your router!!! Afterwards you can turn it back on.
Tested and worked on D5. Hope this helps