Cases T-641/16 RENV and T-137/17: Judgment of the General Court of 13 December 2018 — Kakol v Commission (Staff case — Officials — Recruitment — Notice of competition — Open competition — Non-admission of a candidate to take part in the tests of the assessment centre — Non-recognition of qualifications or diplomas — Admission to a previous competition — Conditions for similar competitions — Concordance rule between the request and the complaint — Res judicata — Non-compliance with the prior administrative procedure — Measure adversely affecting the applicant within the meaning of Article 91 of the Staff Regulations — Competence of the authority which adopted the measure — Claim for damages)