Hi @Rexie 

Thanks for posting in our business forum.

1. Please read how-to guide and give details about what you have tried and your information. Note I don't have to respond to such low-effort queries on my judgment.

And read this article, please.

2. What's your controller version? Is it up-to-date as well?

Hi @Rexie 

Thanks for posting in our business forum.

Rexie wrote

2. Here is the controller information: Model: OC200 v1.0 Controller version: 5.13.24 Firmware version: 1.28.2 Build 20240110 Rel.78776 Troubleshooting being done: -double-check the LAN, no problem, the uptime of other devices including this router is up for around 4 days. -check the logs, it says "failed to adopt". -I tried to "tick" the box in er605 router settings"config->general->Remeber device" but still no good. Diagram looks like this: Internet<--ER605<--SG3210 Switch<--OC200 and access points.

So, my question is what is the error message when it fails?

If you say it is "failed to adopt", then it falls into the categories of this FAQ:

Remember device does not make any difference in this situation.

Hi @Rexie

Rexie wrote

This is the logs looks like "[Failed]Failed to readopt Paloc-GW01 automatically.". -No other information i can find on why it failed to adopt.

I cannot judge based on this information. Reset it and adopt it again. Common way to rule out other possibilities.

I recommend you take a look at the running log and find out if there is a error message indicating the problem.