Case T-655/18: Judgment of the General Court of 13 October 2021 — Aupicon and Others v EEAS (Civil service — Officials — Members of the temporary staff — Members of the contract staff — Remuneration — EEAS staff posted to a third country — Article 10 of Annex X to the Staff Regulations — Annual assessment of the allowance for living conditions — ‘Guidelines establishing the methodology to fix the living conditions allowances’ — Decision fixing the rate of the allowance for living conditions paid to staff posted to Ghana at 20 % — Failure to draw up the questionnaire required by the guidelines — Procedural irregularity — Manifest error of assessment)