I ran into an Update Pilot quirk I was not aware of, and thought it might be useful for others having the same issue.
The problem was UpdatePilot kept timing out and displaying an "error" sign. It was odd, because I had used UpdatePilot before with no issues. It turns out there was nothing really wrong. I just did not know how UpdatePilot decides which WIFI systems it is looking for.
When you use UpdatePilot the first time, it requires you to "select" the internet WIFI and which camera you want to use. If you always update from the same location and using the same camera, no problem. But if you move to a different location, or mount a different camera, you will get an update failure. In my case, I had mounted a different e90 on the H520.
It turns out Update Pilot does not search for WIFI or Camera each time it starts. It remembers the ones you originally selected, and will continue to search for those, and only for those, until you tell it otherwise.
The solution is to use the not-so-obvious Settings Icon in the upper left of the UpdatePilot screen to manually select the new internet WIFI connection and/or the new camera. The H520 manual seems to be a little short on that particular detail. The manual mentions that when you call up UpdatePilot, it will remember the last internet WIFI and camera you used. What it does not mention is if you are not at the same location, you have to manually select a new internet access WIFI, and if you are using a different camera, you have to manually select the new camera. Or both. It does not matter if the ST16S itself is already connected to the new WIFI and/or bound to the new camera. Even if you've been flying around for a week with no problems, the ST16S DataPilot and UpdatePilot don't talk to each other. UpdatePilot is still going to look for the last ones you used for update until you tell it otherwise.
And the manual did not bother to mention that.
Here is the selection process in a nutshell:

The problem was UpdatePilot kept timing out and displaying an "error" sign. It was odd, because I had used UpdatePilot before with no issues. It turns out there was nothing really wrong. I just did not know how UpdatePilot decides which WIFI systems it is looking for.
When you use UpdatePilot the first time, it requires you to "select" the internet WIFI and which camera you want to use. If you always update from the same location and using the same camera, no problem. But if you move to a different location, or mount a different camera, you will get an update failure. In my case, I had mounted a different e90 on the H520.
It turns out Update Pilot does not search for WIFI or Camera each time it starts. It remembers the ones you originally selected, and will continue to search for those, and only for those, until you tell it otherwise.
The solution is to use the not-so-obvious Settings Icon in the upper left of the UpdatePilot screen to manually select the new internet WIFI connection and/or the new camera. The H520 manual seems to be a little short on that particular detail. The manual mentions that when you call up UpdatePilot, it will remember the last internet WIFI and camera you used. What it does not mention is if you are not at the same location, you have to manually select a new internet access WIFI, and if you are using a different camera, you have to manually select the new camera. Or both. It does not matter if the ST16S itself is already connected to the new WIFI and/or bound to the new camera. Even if you've been flying around for a week with no problems, the ST16S DataPilot and UpdatePilot don't talk to each other. UpdatePilot is still going to look for the last ones you used for update until you tell it otherwise.
And the manual did not bother to mention that.
Here is the selection process in a nutshell:
