Spell checking does not work

Spell checking in Kate does not work for Greek language.

Opening kate from konsole, the below are logged:

Hspell: can't open /usr/share/hspell/hebrew.wgz.sizes.
HSpellDict::HSpellDict: Init failed
 HunspellClient::HunspellClient
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0x2c1b7c0
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0x2c1c550
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0x2c2dcf0
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0x5514be0
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0x5514cf0
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0x5514b60
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0xa6d6790
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0xa6da4d0
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0xcfba570
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0xcfc4250
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0x26f64e0
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0xa6d7390
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0x26f6820
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el_GR"
 HunspellDict::HunspellDict( const QString& lang ): "el_GR"
 dddddd 0xa6f8500
 SpellerPlugin *HunspellClient::createSpeller(const QString &language) ; "el"
 HunspellDict::HunspellDict( const QString& lang ): "el"
 dddddd 0x2716dc0
 isCorrect : "ένα"
 result : 0

System:
Description: Ubuntu 15.04
Release: 15.04

Package:
kate:
  Εγκατεστημένα (installed): 4:15.04.0-0ubuntu1~ubuntu15.04~ppa1
  Υποψήφιο (candidate): 4:15.04.0-0ubuntu1~ubuntu15.04~ppa1
  Πίνακας Έκδοσης:
 *** 4:15.04.0-0ubuntu1~ubuntu15.04~ppa1 0
        500 http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu/ vivid/main amd64 Packages
        100 /var/lib/dpkg/status
     4:14.12.3-0ubuntu2 0
        500 http://gr.archive.ubuntu.com/ubuntu/ vivid/universe amd64 Packages

KDE Plasma: 5.3.0 (via backports ppa)