Part of new LoL users unable to create LoL player profile and get the message "Username cannot be found on Riot's servers. Please check your username and try again."
This error in new LoL users on our platform can occur for several reasons:
1) First of all, check if you have specified your server region correctly.
In the first picture you can see that the server region is attached incorrectly:
And immediately after you change to the correct server region, you will be able to continue the registration process.
2)The second reason for this error may be that the issue is on the Riot server side.
Please try to wait for some time and re-go through the registration process.
If nothing helped you, please Submit request to our Support team and we will be happy to solve your issue!