@Nedved27 

With you being in Japan the issue may be different as could the solution.  TP-Link products are region based with signgifant differences between regions based on regulations in that region.  This is why Firmware from one region does not work on a product from another.  Also why we never recommend using a out of region product in a region it wasn't sold in.  We also have a community for users outside of the US  located at community.tp-link.com/en.  You can find the Japanese firmware here:  https://www.tp-link.com/jp/support/download/archer-c5400/#Firmware

We will continue to work on things from our end here and the fix may work for you once its implemented but I mention this becasue of the differences between regions. 

Hi every one.

I have the same problem.

Router: ArcherC5400 v2.0

Firmware: 1.2.2 Build 20170912 rel.56240(5553)

I'm from Brazil.

I put the time manually, but the error don't stop.

Here are a few records from the register. This repeat many times:

---------------------------------------------------------

Hardware Version: ArcherC5400 v2.0
Software Version: 1.2.2 Build 20170912 rel.56240

2019-09-01 05:43:13 led-controller[1099]: <3> 288753 Config importing failed
2019-09-01 05:43:13 led-controller[1099]: <7> 288009 Failed to read WAN_ON
2019-09-01 05:43:13 led-controller[1099]: <7> 288003 Led rule name is WAN_ON
2019-09-01 05:43:13 led-controller[1099]: <7> 288001 Receive data length = 132
2019-09-01 05:43:13 led-controller[1099]: <6> 288051 Start to run WAN1_ON
2019-09-01 05:43:13 led-controller[1099]: <7> 288004 WAN1_ON is found
2019-09-01 05:43:13 led-controller[1099]: <7> 288003 Led rule name is WAN1_ON
2019-09-01 05:43:13 led-controller[1099]: <7> 288001 Receive data length = 132
2019-09-01 05:43:13 led-controller[1099]: <6> 288051 Start to run WAN0_OFF
2019-09-01 05:43:13 led-controller[1099]: <7> 288004 WAN0_OFF is found
2019-09-01 05:43:13 led-controller[1099]: <7> 288003 Led rule name is WAN0_OFF
2019-09-01 05:43:13 led-controller[1099]: <7> 288001 Receive data length = 132
2019-09-01 05:43:13 led-controller[1099]: <6> 288051 Start to run LAN_ON
2019-09-01 05:43:13 led-controller[1099]: <7> 288004 LAN_ON is found
2019-09-01 05:43:13 led-controller[1099]: <7> 288003 Led rule name is LAN_ON
2019-09-01 05:43:13 led-controller[1099]: <7> 288001 Receive data length = 132
2019-09-01 05:43:04 led-controller[1099]: <3> 288753 Config importing failed
2019-09-01 05:43:04 led-controller[1099]: <7> 288009 Failed to read WAN_ON
2019-09-01 05:43:04 led-controller[1099]: <7> 288003 Led rule name is WAN_ON
2019-09-01 05:43:04 led-controller[1099]: <7> 288001 Receive data length = 132
2019-09-01 05:43:04 led-controller[1099]: <6> 288051 Start to run WAN1_OFF
2019-09-01 05:43:04 led-controller[1099]: <7> 288004 WAN1_OFF is found
2019-09-01 05:43:04 led-controller[1099]: <7> 288003 Led rule name is WAN1_OFF
2019-09-01 05:43:04 led-controller[1099]: <7> 288001 Receive data length = 132
2019-09-01 05:43:04 led-controller[1099]: <6> 288051 Start to run WAN0_ON
2019-09-01 05:43:04 led-controller[1099]: <7> 288004 WAN0_ON is found
2019-09-01 05:43:04 led-controller[1099]: <7> 288003 Led rule name is WAN0_ON
2019-09-01 05:43:04 led-controller[1099]: <7> 288001 Receive data length = 132
2019-09-01 05:43:04 led-controller[1099]: <6> 288051 Start to run LAN_ON
2019-09-01 05:43:04 led-controller[1099]: <7> 288004 LAN_ON is found
2019-09-01 05:43:04 led-controller[1099]: <7> 288003 Led rule name is LAN_ON
2019-09-01 05:43:04 led-controller[1099]: <7> 288001 Receive data length = 132

---------------------------------------------------------

I think that this make the router have problems of performance.

In this post below, on post #10, the user say a problem with DHCP on ISP that cause a erro on pic a IP from ISP.

https://community.tp-link.com/us/home/forum/topic/99170

I test here with other router before my Archer C5400.

I put a DHCP Server to define a IP for my Archer C5400.

I tested with IP Dynamic and IP Static. I have the same problem in both tests.

Just a quick tip that worked for me to get by this error:

After the initial setup I got the config error message. After a bit of digging I found that the LED Controller was connecting to the Guest Wireless account by default which did not allow the config to make it through. I disabled the Guest Wireless and tried the setup again and no more config problems or inability to read WAN_ON problems. Afterwards, I was able to turn the Guest Wireless account back on.

Everything works perfectly now, so try making sure your Guest network is OFF and then try again.

Im still having the same issue, no guest wireless was enabled. Wireless continues to drop and the silly config import is the only ERROR showing. its happening daily now. 

I live on the west coast in the USA, so i dont think its geo related. I havent had any issue obtaining the automatic time server and the issue remains whether I set NTP to auto or static. 

What is going on is there a custom firmware I can apply for this?  Support?

@giento I have the same issue and I'm constantly losing internet. TPLink any update?

@digitalintrude 

This log message is the only message that has ever been in the system log going back to the date of purchase, I have not noticed any major problems that couldn't be fixed with a reboot but nevertheless it continues on so I checked the time parameter and it was set to "manual" so I changed it to "get automatically from the Internet" successfully and have yet to see another entry, not that it may not come back, but my question to the TP-Link moderators would be specifically:

What exactly does this error mean and is it anything to be concerned about with regard to the operation and performance of the router or is it just a nuisance error we can all just ignore like the many errors you see on a typical Windows computer.

My Router: Archer C5400 the latest firmware from 9/12/2017, Region: USA, Release: 56240 (5553), Hardware version: 2.0

Time Servers:

time.nist.gov

time-nw.nist.gov

Hope this helps someone :)

Hi,

I'm on latest (1.2.5 Build 20190411 rel.52981) on a ArcherC5400 v2.0 here in Sweden, Europe and have the problems described here as well (including the same ERROR messages in the log) .

It seems like it slowly degrades the wifi until it finally drops it all. Very annoying. A reboot fixes it for a while. Is there any official work-around? Will there be firmware fix?

I will try the toggling of the Guest network and see if that helps. The problem is severe enough that the router needs to be replaced if there's no workaround :-(.

Following this thread as I just started having the exact same issue.

@digitalintrude Also I have this issue.     Also getting regular and random WAN drop-outs on HFC NBN.

Need TP_Link to look more seriously at this - users globally reporting the same thing.  Is this symptomatic of the WAN drop-outs, or unrelated?   

I also had the LEDs permanently off.  A hard-reset, firmware downgrade and firmware upgrade seemed to solve that, but i've never been able to get the NIght Mode (leds go off for a period) to work either.