设置每个用户对已发送消息的最大反应的问题

我正在制作一款黑手党游戏，要让它运行必须有一个投票系统，我想允许每个玩家投一票。

我的代码：

            const VotingMessage = await InnocentChannel.send(`**Player Numbers**\nPlayer 1: ${Mafia}\nPlayer 2: ${Doctor}\nPlayer 3: ${Innocent1}\nPlayer 4: ${Innocent2}\nWho would you like to vote for?\nYou have 1 minute for finish voting.`)
            await VotingMessage.react("1️⃣")
            await VotingMessage.react("2️⃣")
            await VotingMessage.react("3️⃣")
            await VotingMessage.react("4️⃣")

            const {Collection} = require('discord.js')
            const reactionCount = new Collection()

            client.on('messageReactionAdd', (reaction, user) => {

                if (user.id === client.user.id) return

                const VotingMessage = reaction

                const userCount = reactionCount.get(VotingMessage)
                userCount.set(user, (userCount.get(user) || 0) +1)

                if (userCount.get(user) > 1) {
                    reaction.users.remove(user)
                    InnocentChannel.send(`${user.id}, you've already voted for a player, remove a vote to be able to vote for someone else.`)

                }

            })

            client.on('messageReactionRemove', (reaction, user) => {
                if (user.id === client.user.id) return

                const VotingMessage = reaction
                const userCount = reactionCount.get(VotingMessage)
                userCount.set(user, reactionCount.get(VotingMessage).get(user) -1)
            })

当前错误：

userCount.set（用户，（userCount.get（用户）|| 0）+1）。类型错误：无法读取未定义的属性（读取“设置”）