Same here. I've used the old PLC utility that came on CD with the adapter. That worked - and the downloadable tpPLC utility still doesn't to this day.

Would you upload the old version? Seems I dont have the CD anymore.

Try a hard reset?

Or If there is newer firmware then use the recovery utility I posted elsewhere on here and update it.

The problem is with how tpPLC guesses which adapters are TP-Link product and which aren't. Unlike ALL the other vendors, TP-Link PLCs do not have the "vendor" and "product" fields filled correctly - this is a firmware problem. Instead, the "unit name" field is filled with a string that reads "tp_ver_...". tpPLC utility looks for that string.

Now if you rename your PLC adapter units with a generic PLC management tool, TP-Link adapters become unrecognizable, only a factory reset ever brings them back.

To get this right, TP-Link would have to configure their firmware correctly. Note this is true across all series that use Qualcomm chips - AV200, AV500, AV1200.

OK, so a hard / factory reset as above then. To do that, repower the Powerline adaptor and hold down the sync button for about 15 seconds...

I got the same problem as you described, my TP-Link PowerLan Adapter was shown as unknown device in tie PLC-Tool.
But I remembered that I found the PowerLan Adapter in my FritzBox home network. I looked in my Fritzbox home network overview, found the PowerLan Adapter and in the detail page, there was a reset button. After I reseted the PowerLan Adapter, the PLC-Tool found the Adapter as a tp-link device. Now, it works.

... and once you name the TP-Link adapter using the Fritz!Box user interface, it'll be "unknown" to TP-Link software again. See above for why.

No, I only reset the powerline adapter via Fritzbox menu. After the reset, the adapter was correctly shown in the PLC-Tool.