Call to a member function getQueueableRelations() on null

Hi there!

I'm experiencing what I call an X-file... I am creating an application for volleyball leagues and I have created a functionality to generate the days of a league based on the teams that are part of it and divided into two parts:

All code is inside League class.

Code summary:

• A function that generates an array with the information of each game and its match day:

public function generateMatchdays($start)
{
    /* ... */
    if ($teams[$home] !== null && $teams[$away] !== null) {
        $matchday[] = [
            'matchday' => $round + 1,
            'local_team' => $teams[$home],
            'visitor_team' => $teams[$away],
            'date' => $date->format('Y-m-d 12:00:00'),
        ];
    }
    /* ... */
}

• A function that generates the matches and sends an email to the federation and the coaches involved:

public function createGamesFromMatchdays($matchdays)
{
    $games = [];
    foreach ($matchdays as $index => $matchday) {
        /* ... */
        $game = Game::create([/* ... */]);
        $games[] = $game;
        /* ... */
    }

    $federation_responsible = $this->responsible;
    self::sendLeagueMatchesCreatedMail($federation_responsible, true);

    $unique_coaches = collect($games)->flatMap(function ($game) {
        return [$game->localTeam->coach, $game->visitorTeam->coach];
    })->unique();

    foreach ($unique_coaches as $coach) {
        self::sendLeagueMatchesCreatedMail($coach);
    }

    return $games;
}

Now comes the X-file:

✅ If the number of teams is even, everything is executed correctly and the mails are sent.

❌ If the number of devices is odd, I get an error message Call to a member function getQueueableRelations() on null but the matches are inserted correctly into the database, so the problem is in sending emails...

I would really appreciate some help here because I'm a bit stuck. Thank you very much!

Complete code:

public function generateMatchdays($start)
{
    $teams = $this->teams;
    $numTeams = count($teams);

    if($numTeams < 2) {
        throw new Exception('Matchdays cannot be generated with less than 2 teams');
    }

    // If the number of teams is odd, add a "bye"
    if ($numTeams % 2 != 0) {
        $teams[] = null;
        $numTeams++;
    }

    $halfway = $numTeams - 1;
    $matchdays = [];
    $start_date = Carbon::parse($start);
    $date = $start_date->is('saturday') ? $start_date : $start_date->next('saturday');

    for ($round = 0; $round < $halfway; $round++) {
        $matchday = [];

        for ($i = 0; $i < $numTeams / 2; $i++) {
            $home = ($round + $i) % ($numTeams - 1);
            $away = ($numTeams - 1 - $i + $round) % ($numTeams - 1);

            if ($i === 0) {
                $away = $numTeams - 1;
            }

            if ($teams[$home] !== null && $teams[$away] !== null) {
                $matchday[] = [
                    'matchday' => $round + 1,
                    'local_team' => $teams[$home],
                    'visitor_team' => $teams[$away],
                    'date' => $date->format('Y-m-d 12:00:00'),
                ];
            }
        }

        $date = $date->addWeek();

        $matchdays[] = $matchday;
    }

    // Generate return matches
    $return_matches = array_map(function ($matchday) use ($halfway, $date) {
        $match = array_map(function ($match) use ($halfway, $date) {
            return [
                'matchday' => $match['matchday'] + $halfway,
                'local_team' => $match['visitor_team'],
                'visitor_team' => $match['local_team'],
                'date' => $date->format('Y-m-d 12:00:00'),
            ];
        }, $matchday);

        $date = $date->addWeek();

        return $match;
    }, $matchdays, array_keys($matchdays));

    $all_matchdays = array_merge(...$matchdays, ...$return_matches);

    return $all_matchdays;
}

public function createGamesFromMatchdays($matchdays)
{
    $games = [];
    foreach ($matchdays as $index => $matchday) {
        if($index === 0) {
            $this->update(['start' => $matchday['date']]);
        }

        if($index === count($matchdays) - 1) {
            $this->update(['end' => $matchday['date']]);
        }

        $local_team = $matchday['local_team'];
        $visitor_team = $matchday['visitor_team'];

        // Skip "bye" games
        if ($local_team === null || $visitor_team === null) {
            continue;
        }

        $court = $matchday['local_team']->sedes()->first()->courts()->first();

        $game = Game::create([
            'league_id' => $this->id,
            'division_id' => $this->division_id,
            'club_id' => $court->sede->club_id,
            'sede_id' => $court->sede_id,
            'court_id' => $court->id,
            'referee_id' => 1,
            'local_team_id' => $local_team->id,
            'visitor_team_id' => $visitor_team->id,
            'date' => $matchday['date'],
            'requested_date' => null,
            'date_requested_by' => null,
            'matchday' => $matchday['matchday'],
            'start' => $matchday['date'],
            'end' => null,
            'winner_team_id' => null,
            'loser_team_id' => null,
            'status' => null,
        ]);

        $games[] = $game;

        Call::create([
            'game_id' => $game->id,
            'team_id' => $game->local_team_id,
            'locked' => false,
        ]);

        Call::create([
            'game_id' => $game->id,
            'team_id' => $game->visitor_team_id,
            'locked' => false,
        ]);

        Set::create([
            'game_id' => $game->id,
        ]);
    }

    $federation_responsible = $this->responsible;
    self::sendLeagueMatchesCreatedMail($federation_responsible, true);

    $unique_coaches = collect($games)->flatMap(function ($game) {
        return [$game->localTeam->coach, $game->visitorTeam->coach];
    })->unique();

    foreach ($unique_coaches as $coach) {
        self::sendLeagueMatchesCreatedMail($coach);
    }

    return $games;
}

public function createMatchdaysGames($start)
{
    $matchdays = $this->generateMatchdays($start);
    return $this->createGamesFromMatchdays($matchdays);
}

protected function sendLeagueMatchesCreatedMail(User $user, bool $is_federation = false)
{
    Mail::to($user)->send(new LeagueMatchdaysCreated($user, $this, $is_federation));
}