Release 12.1.3: Env A is our central environment, Env B is our SOURCE env and Env C is our TARGET env. On env A, under $FND_TOP/secure, I have A.dbc, B.dbc and C.dbc. I have logged on env A using iSetup resp. and I can only create Instance Mapping row for A env. When I try to create Instance Mapping for B or C, I get error message saying 'File B.dbc or C.dbc' does not exist. Please contact the Web Master or System Administrator'. Our sqlnet.ora also has the value tcp_invited_nodes for envs B and C. Please share what is not being done correctly?