"no valid subkey"

[Michel Messerschmidt]

As an additional hint how to find your encryption key (as opposed to 
signature or authentication keys), you need to look for keys with "usage: E".
In your case it is 0971954D:
$ gpg2 --edit-key 0xB240C11D

pub  4096R/B240C11D  created: 2010-12-10  expires: 2014-11-11  usage: SC  
                     trust: unknown       validity: unknown
sub  2048R/0320F4A4  created: 2014-01-06  expires: 2014-11-11  usage: S   
sub  4096R/0971954D  created: 2010-12-10  expires: 2014-11-11  usage: E   
[ unknown] (1). Erik Josefsson <erik.josefsson at europarl.europa.eu>
[ unknown] (2)  Erik Josefsson (ehj) <erik.hjalmar.josefsson at gmail.com>


-- 
Michel Messerschmidt           lists at michel-messerschmidt.de