Couple of things I noticed in the log:
Your WiFi signal is really poor when the channel is 11, and better when the channel is 1 or 6. The channel used is determined by your router.
Most of the problems occurred when using channel 11.
Not clear what’s going on with the emoncms configuration. The screenshot doesn’t have the key. I assume you removed it for the obvious reason, but I don’t see any other reason for it to fail validation.
There is an issue with restarting upload to the emonpi. It uses an in memory cache to manage the last input date, and that gets wiped when the Pi is restarted. I have asked Trystan about this and there isn’t really a good solution because the data isn’t really retained. This problem is unique to the user version and not emoncms.org.
So changing the upload date is actually a substitute for the missing inputs dates. The IoTaWatt starts uploading from that date, and the Pi is discarding the resulting feed updates that pre-date the last entry. When it finally catches up, the new updates are applied. So resetting the history date in IoTaWatt can save a lot of time after the Pi is restarted. Putting your Pi on a UPS is suggested.
I can’t see any way the emoncms configuration can be lost while the rest of the configuration remains intact. It is one json file, and it’s unlikely that could be removed through some sort of error while retaining the integrity of the rest of the file. The emoncms must have been inadvertently deleted.
If you continue to have trouble adding a new emoncms configuration, restart the IoTaWatt.