MicroCell No Longer Recognizes address

If the address of your cabin is a po box, route number, etc then it's more than likely the GPS coordinates sent by the MicroCell for location verification can not be verified to the local E911 database. This is not an uncommon problem with rural addresses.

What kind of internet service do you have, cable or DSL?

The blinking red 3G light can mean either a hardware failure or an update that didn't reset the MicroCell properly and now the MicroCell "thinks" it is broken. I would try a hard reset of the MicroCell. Turn off the power to the MicroCell, push a paperclip in the reset hole in the back of the unit. Keep holding in the reset button and restore power. Continue to hold in the button for about 30 seconds and then release it. That forces the MicroCell back to factory defaults and starts the Initial Activation process again (see Tech Guide, link in my sig, for the details). If you still get an activation error then it's probably due to the reasons given above, your GPS coordinates can not be matched the E911 locational database for you area. Sometimes AT&T can do a GPS Bypass (basically manally putting your GPS coordinates into the database) but that can not be done by the usual Support group and especially over a holiday week.

The address is a street address, as it was when we initially activated the device. That hasn't changed, nor has the location of the device in the cabin.

We have Charter cable service and a NetGear router, no of thise settings have changed. Cat 6 3' cable to an ethernet port of the router to the device, also not changed.

I thought I had completed a hard reset earlier today, but it was a little different procedure. I'll try the steps you outline.

Strange that it worked from July until now.

There is only one way to properly perform a hard reset and that is the one I posted, and it is also mentioned in my Tech Guide (link in my sig).

AT&T will periodically perform Service Area maintenace, usually late at night, which sometimes requires location verification, usually from the tower closest to you or, if that doesn't work, then from the actual GPS coordinates detected by the MicroCell and sent to AT&T.

Can you confirm your location with Google Maps for example or another GPS device?

I would power cycle your entire setup and then once back up and online, do the hard reset as see what happens. It sounds like erroneous GPS coordinates are either being sent or there is some sort of address error in AT&T's database.

Any power outages or Charter updates that you are aware of that could've changed router settings?

I'll follow your procedure and thanks for the tech guide, very informative. I'll power cycle the entire system, but google and apple maps can both confirm this address.

So after 3 days, multiple reboots, and support telling me to get a warranty replacement, the micro cell unit activated itself overnight. Woke up to see a text congratulating me on my activation and saw that I was indeed connected. So, the 90 minute activation window turned into about 36 hours from my last reboot.

Go figure.

The Registration/Activation site obviously has issues from time to time. It's usually an IT thing in which case Support 1) doesn't have a clue because communication within AT&T is spotty at times and 2) if it is IT, there is nothing Support can do about it but notify IT. Thanks for reporting back. Sorry it took so long.

I have the same issue with my Micro Cell. Working since July and then stopped working about Dec 28th with a red light being indicated on the Network Signal. I also received a text from AT&T saying that the address doesn't match but Microcell was not moved or reconfigured in any way.   This is clearly an AT&T issue. Hopefully mine starts working again as well. I just tried the hard factory reset (power off, hold reset button, power on while continuing to hold down the reset button for 30 seconds) mentioned above.  

Only change that I made recently was that I got a new iPhone and signed up for a 2 year agreement with AT&T. Previosuly I was using AT&T under a bring your own device plan. 

You're not the only person with similar issues (not that it helps you any) so something is obviously amiss here. It's a holiday weekend so not much will probably get done. I will link your post to the Admins on Monday and we'll try from that angle. In the meantime, send a pm to CustormerCare (link in my sig) with your problem, any assigned trouble tickets, what you have done to correct it, your account info, the best way for them to contact you, and your location.