When the FairCom RTG ctree.conf configuration file included a <localinstance> or <redirinstance> section, passing an invalid file handle resulted in a BTRV error 19 (B_UNRECOVERABLE_ERROR) instead of 3 (B_FILE_NOT_OPEN). The logic has been modified to return the correct error in this situation. In addition, c-tree error 53 FTYP_ERR has been mapped to BTRV error 88 B_INCOMPATIBLE_MODE_ERROR.