it (half-)bricked mine (2 EAP245v3) too.  Standalone web interface still works.

Regarding "Tried resetting via tftp, to no avail. The access point is requesting the firmware ("EAP245v3_up.bin") and I see successful transfer of the complete file, but the access point is not flashing the firmware onto the device.", it may be because the unit is on 5.2.0 already.  If you tftp something else, then back to 5.2.0, device would flash it normally.  But it did not solve the problem.  

  @eshmh Send an email to support. They offered RMAing mine. Don't know anohter fix.

Btw. I tried flashing "something else", which means prior firmware versions. And mine didn't accept those. They stuck with 5.2.0.

  @egonsmith I flashed the earlier version firmware(s) via tftp.  I first tried to do it via the web, AP said file not right or something.  At least, the APs are usable on 5.0.5.

Exact same thing happened to my EAP245v3 (US) - both of them bricked. But mine were updated by the controller with the official version, not a beta or pre-release. Baffling given that TP-Link had been made aware of the issue (by way of contacting support) during the beta period.

Edit: Thank you for sharing, I was going crazy...

  @egonsmith Same thing just happened to me. Really wish I'd known about this ahead of time, or done 5 mins of research before grabbing the .bin and pushing it out to three APs in a row... seems to be plenty of others experiencing issues related to 5.2.0. This firmware completely screwed them all up. Can't connect to 5GHz SSIDs, falls back to 2.4GHz if there's an SSID with the same name present. If not, jut doesn't connect at all. Lots of 5GHz settings have disappeared. There's a page where a 5GHz tab is next to 2.4GHz very briefly and then it disappears. Some 2.4GHz settings are missing (drop-downs with no options in them under the radio settings, for instance). Other areas of the management site show information related to 2.4GHz when it should be showing 5GHz related data (channel & link speed for instance - there's no such thing as channel 11 on 5GHz...) Speeds and range have taken a severe nosedive, obviously. This is absolutely unacceptable. This is something that should have been caught during the multiple YEARS since the last stable release; 5.1.0. I'm beginning to wonder if this was by design; break everyone's APs to force a hardware upgrade...

This is on 3 idenitcal EAP245v3 (US) APs. These APs had originally been bought new & sealed from Amazon, and came loaded with Canadian firmware (odd, but apparently not uncommon, have seen lots of others get US hardware with Canadian firmware on it). I had successfully pulled 5.1.0 US firmware to them using Tftpd after the management interface would not accept the US .bin file. That was great firmware; Good speeds, compatibility, range, stability, etc. Now I've had to revert to 5.0.5 CA firmware just so the damn things are functional (albeit slow as molasses, I'm only getting 153Mbps on 5GHz in the same room - all combinations of channels, channel widths, etc have been tried - the Canadian firmware just seems to be nerfed, or 5.2.0 has done something to the AP because I don't remember 5.0.5 CA being this limited/slow previously).

I'm about to send an email to support in hopes that they will RMA these units and send me ones that can successfully have the 5.1.0 US firmware pushed to them. If not, I'm off to Ubiquiti and will never give my business to TPLink again, nor will I recommend them to others. This is supposed to be reliable enterprise-grade hardware, not toy-like consumer-level junk. There's no business in the world that would accept this outcome, and rightfully so. Do better, TPLink.

Piling on with the same issue. Omada controller pushed out 5.2.0 to my EAP245 (US) v3.0 and the AP showed disconnected after the update.

I was able to perform firmware recovery via tftp, but had to go back to 5.0.5. 5.1.0 will cause the AP to behave as if it has no radios. Unfortunately this device now has reduced functionality on the 5.0.5 firmware and I don't trust it.

  @egonsmith I had the same problem with the EAP265v1 and got it working again by downgrading to 5.0.5 then upgrading to 5.1.0 but the mesh and settings seem to be missing in the controller.  Anyone find a work around for this?

  @egonsmith Not bricked, but my 2 AP's were very unstable after firmware 5.2.0. I was able to downgrade them again to 5.0.6 and all has been smooth sailing since. 

  @xyphur I had the same issue with my v3, they were CA but flashed US and had them at 5.1.0.  Flashed to 5.2.0 and they stopped working had to TFTPd them back to CA firmware but stuck at 5.0.5.  Would be nice if either TP link updated the CA firmware to match what is available elsewhere or not have the US firmware screw up the CA hardware.  Screw ups like this make it less and less likely that I will stay with TP link.

Glad to see i am not the only one, one of my 245v3 flashed to 5.2.0 while the other bricked and was only able to recover using 5.0.5. Both of mine previously were running 5.1.0.

If you repeatly flash 5.1.0 (at leat 4 times) it will flash and boot up, however it will not adopt, 5ghz is broken and cannot be factory reset at all. Only way to get it functional is to flash back to 5.0.5.