Ethernet has no valid IP configuration, fix?

Have been having this problem for several days. WLAN connects normally, but my DEVOLO Ethernet is no longer working. Restarting the router and the laptop will not help. Troubleshooting always means only the following:

"Ethernet" does not have a valid IP configuration

How do I fix this again?

Your laptop has no connection to your router, because he can't retrieve the automatic IP configuration (which he always gets when starting the laptop). LAN plug in the router and in the Devolo's neatly plugged?

Look at the indicator lights (LEDs) of your devolo adapter (s) and then look up the meaning of the LEDs in the manual.

Unfortunately, you have not written which devices you use from Devolo.

Your problem should be on the dlan route. The question that arises is only whether it is one of the dlan adapter, or the disturbance is otherwise caused z.b. Through new devices etc…

maybe it helps, if not done yet, the dlan plug, instead of a multi-pin connector in a permanently installed socket accommodate.

Have a Devolo Dlan 500 Wi-Fi plug. Plug are all indoors. Also with the router.

Plugged into the socket, the adapter in front of it were otherwise no devices.

Have you already installed the configuration program "Devolo Cockpit 5.0.4 Windows" on the PC? If not, then download this one here:

https://www.devolo.de/support/downloads/download/dlanr-500-wifi-powerline

and give it a call. It shows you the current situation and offers good help with problems with devolo adapters.

What do the LED display on both devolo adapters (red, green, flashing…) look like in the manual: https://www.devolo.de/support/downloads/download/dlanr-500-wifi-powerline

PS:

There's even a firmware update for devolo adapter (already made the update)? If not, then I would do it. IMPORTANT! A firmware update must never be canceled, so be careful when importing the update! Here is the firmware update: https://www.devolo.de/delos-update-fuer-dlan

Addendum: Look at my general statements about this answer:

Use only LAN s.PC and turn off the WLAN s.PC, because a double connection to the router (via WLAN and simultaneously via LAN) is cheese and provokes disturbances s.PC.

Thanks, with which program do I open the firmware update?

Here it is described how a (firmware) update is made.

https://www.devolo.de/delos-update-fuer-dlan

Step 1 Start Cockpit…

Step 2 Press the button "Update"… Etc.

As I understand it with the program "Devolo Cockpit 5.0.4 Windows". In this program there's then the button "Update" (see step 2).