@NikosK Try this guide, https://www.tp-link.com/us/support/faq/2983/ , it worked for me.  

@NikosK 

When you adopt a device all previous setting will be lost because they need to be in sync, and may not be compatible, with the controller settings.  So adopt first then make all required settings.  Router/EAP password is either going to be the default admin/admin, whatever you changed it to, or are listed under Settings>Site "Device Account" on the controller.  Should be able to reset EAPs using their IP address in a browser.

@1207  the password isn't anything known,  I be tried everything, the unit password,  the omada password.  Nothing worked.  If it was known then the controller should automatically fil it,  but adoption failed due to wrong login/password.

Is it logical to change the password instead of memorising it.  Now I need to physically reset each access point in the building...

My experience has been the controller uses the default password admin/admin during the first attempt to adopt. If you have changed the device's password in standalone mode, it will fail and then ask you to provide the correct password. If I enter the password the adopt continues and is successful. This has been using the OC200 hardware controller. So yes, the device should remember the password you set in standalone mode.

@NikosK Try that guide I posted above. Adoption will fail claiming incorrect password if there is a subnet mismatch. You need to a follow a certain set of steps if your devices are set up on .1.x

@NikosK 

After equipment is adopted into the controller it is managed through the controller, i.e. direct login is lost. So you would adopt devices and then configure them in the OC200 after that. This is normal procedure for enterprise level APs so there are no setting conflicts, and makes sense with a software defined network for the same reason.

The most infuriating part is that when I connect the router works for a minute as intented. I can see the configuration of my router in the omada controler, but I can't save it or do anything with it., Then the controler erases everything for "compatibility" issues destroying my work again and again.

If the controler can read my settings it should be able to ask me what I want to keep  and create a new "compatible" profile to use.

The creator of this piece of junk is responsible for all these issues.

I 've read https://www.tp-link.com/us/support/faq/2983/ and I find no new info. I had already changed both the OC200 ip and falllback ip to the 192.168.1.x range and used the same range for the router. But then the "adoption and provisioning" happens, where the controler change the lan to 0.x and the password in every compatiblle tplink product, locking me out from me network. I don't want to  use the 0.x range, I have a lot of equipment with static ips. I want to config my network as I LIKE.

@NikosK you don't need to use 0.1. After you provision the router from the oc200, you change it back to 1.1 and switch the oc200 back to using DHCP.

Yes this should be the correct thing to happen but.... After "reseting" the configuratin to 0.1 the controler fails everytime to adopt the router. I, on the other hand have no access to the router due to the change of the login/password( no it is not the old password or the controler login/password) and the only solution is to reset everything and try again.

@NikosK 

Does the default account work on the router after reset? As long as it does,  I would check that you are on the latest firmware for everything.  After that don't set a configuration on the router and try adopting it again.  The default management LAN is 0.1. In the latest firmware you can now change this,  but unless you do,  you probably want to keep that LAN configured for the management aspect and setup separate LANs for the rest of the network.  You might also try setting it to adopt and leaving it alone for a little while. I have read some people do that and it automatically adopts after a few attempts.