@Bushyhead 

I had a similar problem, after resetting the access points I had to login to each AP individually set a password then adopt then to the controller again

@Fae 

Many thanks for your reply. 

When pressing the reset button, after about 5 or 6 seconds the LED flashes orange & green quickly several times, it then goes back to solid green for a couple of seconds and then flashes orange once more then back to green. After this the green light blinks every 5 seconds or so. There is never a yellow light when doing the reset only green and orange lights. 

After doing the reset, when I go to cloud controller and try to adopt the device it immediately comes up with a box that says 'The username and password of this AP have been changed. The Omada controller cannot adopt it automatically. Please enter the correct username and password for the device'. I enter the username and password that is shown under 'Device Account' on the controller but I then get an error message saying 'Failed to adopt the device because the username or password is incorrect'. I have also tried inputting admin/admin but I still get the same error message saying incorrect username or password. 

I've tried inputting the passwords through cloud controller on PC and via IOS App but neither works. 

Unfortunately I don't get to the opportunity of logging in as after resetting the AP as it doesn't accept the default username & passwords of admin/admin. How did you manage to login?

@Bushyhead 

I have finally solved this problem. The Cloud Controller software repeatedly would not accept the admin password even though it was the correct one as I had reset each unit, this made me think that the reset wasn't working. In fact the reset was working. I had to connect each EAP directly to my laptop via LAN and then go into each unit through the IP address of 192.168.0.254 then change the password to something simple. I then connected each via LAN to the router/switch so that the Controller could adopt each unit. Occassionally when disconecting from the routher LAN the unit would go into isolation so I connected directly to it with a cable and did a reset, the controller then adopted each unit again and the unit did not switch into isolation mode. 

Hope this helps anybody else having the same problems.