flat file schema test exception

I’m new to webmethods and just want to try a fixed length flat file.
The file is simple: T12123 with schema:
record parser: fixed length
record length:6 (5 not work)
record identifier: starts at position 0
document definition: Test
record definition: T
field definition: f1, mandatory, position 1-3 (starts from 0, not work either)
field definition: f2, mandatory, position 3-6

The encode is UTF-8, and the file failed the test with
com.wm.ui.UIException:com.wm.ff.parse.ParseException [FFP.0012.0004]
Found no valid records

Can anyone tell me why or where can I find some examples?

Thanks.

Record names in schema are case sensitive. How ever you given in schema the same name should be in your flat file input. Compare your schema record names and input flat file record names.