OpenAm doesn't create users when OAuth authentication enabled - openam

Question

I have two instancies of OpanAM. One works as OAuth2 provider, the second works as OAuth2 client.
When I enable option "Map to anonymous user" on service instance, all flow works fine - client redirects me to provider, where I enter my username and password, then it redirects me back to client where I can see my new anonimous profile.
But in my case I need to map user from provider to client when user logins to my system.
When i enable function "Create account if it does not exist" when I apply consent screen it redirects me back to client and I see this error message: "Unknown error. Please contact your Administrator".
I have enabled logs and in logs I see this error:
org.json.JSONException: JSONObject["sub"] not found.
org.json.JSONException: JSONObject["name"] not found.
org.json.JSONException: JSONObject["given_name"] not found.
org.json.JSONException: JSONObject["family_name"] not found.
ERROR: unknown callback null
When I perform REST-request to provider on userinfo endpoint with Postman it returns me this JSON:
{
"sub": "user123",
"name": "name",
"given_name": "gn",
"family_name": "fn"
}
Based on this response, I configure mapping in OAuth2 module on client OpenAM this way:
Account Mapper Configuration:
sub=sub
name=name
given_name=given_name
family_name=family_name
Attribute Mapper Configuration:
sub=sub
name=name
given_name=given_name
family_name=family_name
Thanks!