スクラップメカニックのエラー表示一覧：ジョイントと建造

The messages are a fixed list, and it is short

Scrap Mechanic shows alerts as a short banner and then moves on, which is why so many of them get typed into a search box word for word. The list is fixed. Everything below is the exact wording the game uses in English, grouped by the situation it belongs to.

Two of these messages, “Invalid joint positions” and “Joint connection error”, get searched more than the rest put together. Both belong to the same family: they appear when the game refuses to complete a build or placement request. What follows is what can be said about them without inventing a cause.

Build and placement alerts

These are the alerts the game raises when a creation cannot be built or placed as requested.

Message	What it is about
Invalid joint positions	A joint in the requested build could not be accepted where it was asked to go
Joint connection error	A joint in the requested build could not be connected
Controller connection error	A controller connection in the requested build was refused
Insufficient parts	You do not have everything the build needs
Non existing shape	The build refers to a part the game cannot resolve
Empty rigidbody	The request contained a body with nothing in it
Failed to build shape	The build request failed while the shape was being created
Invalid JSON	A file the game was asked to read is not valid
Failed to parse JSON	A file the game was asked to read could not be parsed

The honest caveat belongs here rather than in a footnote. The game does not publish which player action produces each of these, and the messages themselves do not name one. What the grouping does tell you is that they are refusals from the build path, so the useful reaction is to look at the creation you were placing rather than at your graphics settings or your install.

What to actually do about a joint error

Work on the creation, one change at a time. Joints are bearings, pistons and the other parts that connect two bodies, so a creation with a lot of them has more chances to hit a refusal than a solid block of blocks does. The blueprint analyzer reads a local blueprint file and reports how many joints, controllers and separate bodies it contains, which turns “this thing is complicated” into a number you can compare against a version that worked.

If the creation came from someone else, check whether it needs a mod. A part that is missing on your machine is not the same problem as a joint that will not connect, but it lands in the same build path.

Connection limit alerts

Message	What it is about
Max connections reached	The connection limit for that part has been hit
Max bearing connections reached	The bearing connection limit has been hit
No connections	The action needed a connection and there was none
Controlled by another interactable	The part is already being driven by something else

These four are limits rather than faults. “Controlled by another interactable” is the one that confuses people most, and the wording is the answer: something else is already driving that part, so the new connection is refused until the old one is removed.

Tool and interaction alerts

Message	What it is about
Unable to collect all parts	Not everything you tried to collect could be collected
This stone is too big for the sledgehammer	The stone needs a different approach
This tree is too big for the sledgehammer	The tree needs a different approach
Make sure you remove the lift before using the Driver’s seat	The lift is in the way of driving
Make sure you place the Builder Guide on the Lift to activate it	The Builder Guide only works on the lift
This Seat is occupied	Somebody is already in that seat
YOU’RE NOT THE CREATOR OF THIS CONTRAPTION	You are not the creator of the creation you acted on

The two sledgehammer messages answer a question a lot of new players ask in a roundabout way: the tool has a size limit, and the message is telling you that this particular stone or tree is over it rather than that your hammer is broken.

Survival status alerts

Message	What it is about
UNAUTHORIZED FARMING DETECTED!	A raid has been triggered by your farm
Hungry	Hunger status
Thirsty	Thirst status

“UNAUTHORIZED FARMING DETECTED!” is the one that sends people looking for a fix. It is not an error. It is the raid system telling you that what you planted crossed a threshold, and it behaves exactly as designed. The raid calculator turns your crops into the raid level they add up to, and how to stop raids covers the ways to keep the total under control.

Hunger and thirst appear in the shipped message list, but 1.0 Survival runs on health alone, with no hunger bar and no thirst bar to manage.

Error message questions

What does “Invalid joint positions” mean in Scrap Mechanic?

It is the alert the game shows when a joint in a build or placement request could not be accepted at the position it was asked for. The game does not publish the exact condition behind it, so the practical response is to change the creation, not the install: simplify or rebuild the joint area and try again.

What is the difference between “Invalid joint positions” and “Joint connection error”?

Both are refusals from the same build path, one about where a joint was placed and one about the connection itself. Neither has a published trigger, and neither indicates a corrupted install.

Why does it say “Controlled by another interactable”?

Because the part you are wiring is already being driven by something else. Remove the existing connection before adding the new one.

Is “UNAUTHORIZED FARMING DETECTED!” a bug?

No. It is the raid warning. Crops add up to a raid level, and once the total passes a threshold a raid is scheduled against your farm.