FreeIPA: command-line tools do not work, 'No Kerberos credentials available'

Alex asked:

We have a working FreeIPA installation, it’s in production since February. Almost everything works as expected but when we try to run command-line FreeIPA-related tools none of them work:

[admin@ipa ~]$ kinit admin
Password for admin@EXAMPLE.COM: 
[admin@ipa ~]$ klist
Ticket cache: KEYRING:persistent:8800000
Default principal: admin@EXAMPLE.COM

Valid starting       Expires              Service principal
06/30/2014 21:19:30  07/01/2014 21:19:12  krbtgt/EXAMPLE.COM@EXAMPLE.COM
[admin@ipa ~]$ ipa pwpolicy-show global_policy
ipa: ERROR: Kerberos error: ('Unspecified GSS failure.  Minor code may provide more information', 851968)/('No Kerberos credentials available', -1765328243)
[admin@ipa ~]$

I’m not a Kerberos expert and don’t really know what to check. How can we debug and resolve this?

Update: when I add -vv I get the following:

[admin@ipa ~]$ ipa -vv pwpolicy-show global_policy
ipa: INFO: trying https://ipa.example.com/ipa/xml
ipa: INFO: Forwarding 'pwpolicy_show' to server 'https://ipa.example.com/ipa/xml'
ipa: ERROR: Kerberos error: ('Unspecified GSS failure.  Minor code may provide more information', 851968)/('No Kerberos credentials available', -1765328243)
[admin@ipa ~]$

Update 2: the content of /etc/krb5.conf follows:

includedir /var/lib/sss/pubconf/krb5.include.d/

[logging]
 default = FILE:/var/log/krb5libs.log
 kdc = FILE:/var/log/krb5kdc.log
 admin_server = FILE:/var/log/kadmind.log

[libdefaults]
 default_realm = EXAMPLE.COM
 dns_lookup_realm = false
 dns_lookup_kdc = true
 rdns = false
 ticket_lifetime = 24h
 forwardable = yes
 default_ccache_name = KEYRING:persistent:%{uid}

[realms]
 EXAMPLE.COM = {
  kdc = ipa.example.com:88
  master_kdc = ipa.example.com:88
  admin_server = ipa.example.com:749
  default_domain = example.com
  pkinit_anchors = FILE:/etc/ipa/ca.crt
}

[domain_realm]
 .example.com = EXAMPLE.COM
 example.com = EXAMPLE.COM

[dbmodules]
  EXAMPLE.COM = {
    db_library = ipadb.so
  }

Update 3: This is a single-server installation, the distro is Fedora 19 and FreeIPA version is 3.3.5