Invalid Panel Size when sending across WAN

Dropped packets or a bad connection (as in, it connected, but not real well - noisy or spotty). You get this error when the panel doesn't report back what TPD was expecting. You can sometimes get it when there is no real connection at all, so in that it may even be deceptive. I've always found TPD3 to be impossibly slow for remote loads; you have to pass your file through the master, then across the Axlink buss (which is slow, slow, slow). There's just too much to go wrong. Don't get me wrong, it can be done (and I have done it), it's just real finicky.

Another possibility is that your AXT-MCP/PB is asleep. I'm not terribly familar with that model but if you try to load to an VPT-CP, for example, you will get that error if it's not awake. Connect via terminal to the master, and send the panel a WAKEUP command first and see it that works.