SNMPTable get "Was that a table?" error. Why?

[Lucian R. <rom...@gm...>]

I tried to get data defined in table by this
$ snmptable -v 2c -c public 10.0.13.1 -Os .1.3.6.1.4.1.27594.3.6
and got this
Was that a table? enterprises.27594.3.6
I already had this MIB definition in ~/.snmp/mibs/
So what's the problem and how to solve it. Thanks.