I've seen that error so often now that I hardly even notice it--except that often it blocks my view of something important. It's possible to dismiss the error dialog, but it's not easy. That little "X" button is so small that I usually end up poking at it 5 or 6 times, and because it's a WinCE error, the iFly remote control won't get it.
There may be a workaround if it's possible stop the 740 from connecting to the uAvionix Ping wifi router. I haven't tried it only because I like to use the Traffic instrument on the 740 to alert me to traffic and the EFIS on the iPad to see traffic in 3D for better situational awareness.
I got tired of PA not having any way to fix this bug and instead telling me to download yet another update from the uAvionix website. I phoned uAvionix months ago and talked with a really crabby guy who claimed to have written an update but that he had been prevented from posting it there. I downloaded it from an unofficial URL he gave me, but it didn't stop the error messages on the 740. As far as I know, there still is no update that addresses this bug.
I'm calling this a bug because it prevents the 740 from working properly. AP people seem to think it's a uAvionix problem, and uAvionix blame it on AP. And that bugs me.