Forgerock AM 7.3 oauth2 configs

Question

I have configured the 1st AM as provider,2nd AM as client.

1. rs1.abc.com - Oauth2 provider, with client config

2. rs2.abc.com - acting as client with oauth2node tree with openid connect along with with dynamic provisioning for creating users dynamically.

Redirection to client works well, but I get

1. Login Failure
2. In the debug logs - snippets follow

ERROR: DefaultAccountMapper.getAccount: IRE com.sun.identity.idm.IdRepoException: Invalid Identity attribute username - (usr!jrp) contains one or more invalid characters [, (, ), &, !*

ERROR: Exception in processing the tree org.forgerock.openam.auth.node.api.NodeProcessException: Unable to create user

Correction pointer will be helpful and very much appreciated.

Thanx, JP

I tries using Forge rock AM with Embedded DS and also external DS. Result is the same.