Nottingham Forest has been fined £750,000 and received a warning regarding future behavior after making disparaging comments about VAR referee Stuart Attwell on social media in April.
The Premier League club had denied that the comments brought the game into disrepute by implying bias and/or questioning the integrity of match officials.
An independent regulatory commission found the Football Association charge proven.
Forest felt they should have been awarded three penalties during a defeat at Everton last season and after the game, they posted on their official X account: "Three extremely poor decisions - three penalties not given - which we simply cannot accept.
"We warned the PGMOL that the VAR (Attwell) is a Luton fan before the game but they didn't change him. Our patience has been tested multiple times. NFFC will now consider its options."
TrendingForest were in a relegation battle with Luton last season, but ultimately stayed up, while the Hatters were relegated.
Forest declined to comment on the sanction.
Forest also asked to listen to the VAR audio from the game, a request which Professional Game Match Officials Limited (PGMOL) granted.
The club also called for PGMOL to take into account "contextual" rivalries when making referee and VAR appointments, but when the allegiances criteria were published at the start of this season this was not included.
On the day Forest were charged, their referee analyst Mark Clattenburg left the club having been given a formal warning by the FA over his comments about Attwell.
Comments made by manager Nuno Espirito Santo and defender Neco Williams in relation to the officiating at the Everton game also resulted in sanctions, with Nuno given a suspended one-match touchline ban, a £40,000 fine and a warning as to his future conduct, and Williams also warned and fined £24,000.