> ## Documentation Index
> Fetch the complete documentation index at: https://docs.splox.io/llms.txt
> Use this file to discover all available pages before exploring further.
# When a change makes it worse
> The agent changed something and now the agent is worse: how it looks, how to say it, how to go back, and when to start over
You asked for something, your agent edited itself, and now it is worse than it
was an hour ago. This is the normal failure of a system where the agent writes
its own code, and it has a normal fix: say what changed for the worse, and go
back.
The one thing not to do is keep asking for fixes on top of a bad change. Three
corrections later you have a version nobody understands, and the version you
liked is still sitting there, one sentence away.
## What it looks like
**Everything comes out in the wrong shape.** Answers that are suddenly one line,
or five times too long, or in a language you did not ask for. That is a prompt
change that overshot — `programs/splox/prompts/assistant.md`, edited on your
behalf, doing exactly what it now says.
**It stopped doing something it used to do.** It no longer reaches for a tool it
used yesterday, or it refuses a kind of command it used to run. Either the tool
came off its list or a rule was added about what it may do.
**Every turn fails at the very start**, with a message naming a file:
```
programs/splox could not say who "Assistant" is: KeyError: 'TELEGRAM_BOT_TOKEN'
```
```
programs/splox could not say who answers this message: SyntaxError: …
```
That is the platform asking `main.py` who should answer and not getting an
answer. Nothing else in the harness ran; the file that is quoted is the one to
fix. This shape is worth recognizing because it looks catastrophic and is
usually a one-line mistake.
## Say what changed, not what to do
The useful sentence names the behavior and when it started:
> Since you added the expense ledger, you answer everything in one line, even
> when I ask you to explain something. Go back to how you were before that
> change.
> You have stopped reading files before editing them. That started this morning.
> What changed, and can we undo it?
Your agent can read its own history — every publish, its message, its date — so
"since you added the ledger" is enough to locate the change. It does not need
you to know which file.
If you are not sure a change is even the cause, ask first:
*"What have you changed about yourself today?"* Reading the history costs
nothing, and it is often the whole diagnosis.
[Versions](/inside/versions) is that page.
## Going back
Say it plainly:
> Go back to the version before the ledger.
What happens: your agent publishes a new version whose contents are the older
one. Nothing is deleted, the numbering only ever goes up, and the version you
rolled back from is still there if it turns out you wanted part of it.
Two things it does **not** undo, and they surprise people:
* **Files.** Anything the agent wrote to the machine stays written. A rollback is
about who the agent is, not about what it did. If a change also produced a bad
file, say so as well.
* **Programs it started.** A bot or a nightly job that is already running keeps
running the code it was started with. Ask it to restart the program after the
rollback.
Wait for the turn in front of you to finish before asking for a rollback. A run
already going keeps the agent it started with, but it re-reads its hooks and its
tool files as it goes — so rolling back underneath a long turn can change how
the rest of that turn behaves.
## Going back only here
If the change is fine in general and wrong for one machine — you want to
reproduce something, or keep one machine steady while the other moves — the
machine can be pinned to an older version instead of the harness being rolled
back. Ask for it in those words: *"pin this machine to version 4 and leave the
rest alone."* Nothing is published and no other machine moves.
## When to start a fresh machine instead
Rolling back fixes the agent. It does not fix the computer. Start a new machine
when the problem is the machine:
* **The disk is gone.** *"The files this machine kept are not on the runner any
more."* There is no button that brings it back and no amount of retrying helps.
* **The machine will not start** for any reason that is not your plan's machine
limit.
* **The disk has filled up with something you cannot untangle**, and starting
clean is cheaper than archaeology.
A new machine on the same harness is a fresh computer with the same agent: it
checks out the same published version and knows nothing your old machine wrote
down. Copy what you need off the old one first — see
[Files](/inside/files) — because deleting a machine deletes its disk.
[Troubleshooting](/troubleshooting) has the exact wording of each of those
refusals and what causes them.
## When it is not the change
Two failures look like a bad edit and are not:
* **A run refused because a usage window is full.** The agent stops mid-task and
says when the window resets. Nothing about it changed. See
[When a limit is reached](/account/limits).
* **A tool that lost its credential.** A connected server whose token expired
fails inside the run rather than at the start, and says so in the tool's own
words. Reconnect it under [Connections](/app/connections).
Reading the history and going back, step by step.
Every failure the product actually produces, quoted.