Tried to connect to a database in restricted mode, but it failed with ORA-01035.
ORA-01035: ORACLE only available to users with RESTRICTED SESSION privilege
ORA-01035 means that the listener refused to establish the connection because the user didn't have RESTRICTED SESSION system privilege to connect to the database successfully.
To solve ORA-01035, we'd better grant the right privilege, i.e. RESTRICTED SESSION to the user.
SQL> conn / as sysdba
SQL> grant RESTRICTED SESSION to hr;
Of course, you can also ask DBA to remove restricted mode from the database.
To connect a restricted database as SYSDBA, there're more details.
Kindly remind you that, don't grant RESTRICTED SESSION privilege to a normal user unless you have a good reason to do so.