The precise message link is here:
https://discord.com/channels/500413814244638747/758543626069737503/982733901724282900

Save as FixUnmountableCars.cs:

using System;
using Oxide.Core;

namespace Oxide.Plugins
{
    [Info("Fix Unmountable Cars", "Substrata", "1.0.0")]
    [Description("Fix Unmountable Cars")]

    class FixUnmountableCars : RustPlugin
    {
        [ChatCommand("fixcars")]
		void cmdFixCars(BasePlayer player, string command, string[] args)
        {
            if (!player.IsAdmin) return;
            FixCars();
        }

        void OnServerInitialized(bool initial)
        {
            if (initial) FixCars();
        }

        void FixCars()
        {
            foreach (var ent in BaseNetworkable.serverEntities)
            {
                if (ent is ModularCar) FixCar((ent as BaseVehicle));
            }
        }

        void FixCar(BaseVehicle vehicle)
        {
            if (vehicle == null || vehicle.IsDestroyed || vehicle.AnyMounted()) return;
            vehicle.DismountAllPlayers();
            vehicle.SetFlag(BaseEntity.Flags.Reserved11, false);
        }
    }
}

That plugin only affects cars, but I've seen people saying the issue happens to "vehicles" so it's not clear how far reaching the impact is.

Juggernaut

Seems like a game bug.

Can be fixed with

car.SetFlag(BaseEntity.Flags.Reserved11, false);

Substrata posted a small plugin to fix the issue in the Umod Discord.

send me a pm if you need a copy, not sure how to link to a discord post.

Ty for the help

WhiteThunder

The precise message link is here:
https://discord.com/channels/500413814244638747/758543626069737503/982733901724282900

That plugin only affects cars, but I've seen people saying the issue happens to "vehicles" so it's not clear how far reaching the impact is.

thank you for help :) it works now ;)

First, I apologize. It could be a coincidence. After installing the plugin and after restarting the server, I found a bug. All the cars that were in the world, as well as the players on the lift, stopped working, i.e. you can't sit in them.

I repeat that it may be a coincidence, but I have no other thoughts.(

I checked, apparently this is a game bug.

Ok first I want to think everyone for letting me know it was not me as this has been driving me nuts!
but the links are not working and I for the life of me find the post on there discord thanks.

ToxicGamer67

Ok first I want to think everyone for letting me know it was not me as this has been driving me nuts!
but the links are not working and I for the life of me find the post on there discord thanks.

you need to join the umod group and react to rust role for link to work

WhiteThunder

The precise message link is here:
https://discord.com/channels/500413814244638747/758543626069737503/982733901724282900

That plugin only affects cars, but I've seen people saying the issue happens to "vehicles" so it's not clear how far reaching the impact is.

hi the link ist not working foe me

Thx :)

is this still needed since the recent updates? I took it out nobody has complained

I still have the problem. Can someone tell me how to proceed further. Thanks

Kobani

I still have the problem. Can someone tell me how to proceed further. Thanks

Download FixUnmountableCars.cs from above links install it and either type /fixcars or restart server 

I've still been experiencing this issue so have been using this continuously.

The links point to Discord. But I can't find FixUnmountableCars.cs there...

The link I posted earlier seems to have been removed. You could always copy the code from the original post by WhiteThunder at the top of this page and save as FixUnmountableCars.cs