Opening it
Press Win+R, paste this, press Enter:
%LocalAppData%\w0a\errors.logIf Windows asks what to open it with, choose Notepad. It is a plain text file.
If the file is not there, nothing has been written yet. It is created with its first line.
Reading a line
Each line starts with a running number, then the date and time, then the part of w0a that wrote it in square brackets, then what happened. A failure that threw an exception is followed by a few indented lines naming the methods it passed through. Those carry no source paths or line numbers, because the release build ships without them.
The newest lines are at the bottom.
Two kinds of line are not faults:
- A line whose message starts with
NOT-A-FAULT:is an engine saying there was nothing for it to do on this PC — no wireless adapter, a setting already where it wanted it. It is written once so that "did nothing" can be told apart from "never ran". - A failure that repeats is not written every time. The first one is written, then the gaps between written copies grow, and each copy that is written says how many were folded since the last one. A loop failing every two seconds then shows up roughly twice an hour, not as a full file.
What is in it
A dated line for every failure w0a caught and where it happened. Nothing is silently swallowed: a hardware query that failed, a registry write that was refused, a page that would not load — it is here.
That is the point. An application that hides its own errors behind a friendly message cannot be diagnosed.
What is not in it
- No list of your files, folders or games. An error message can name a path when a file operation fails; that is the only way a path gets in.
- No licence key. Nothing in w0a writes the key to this file.
When it leaves your PC
The file stays on your disk. Its lines leave in two ways, and both remove your account name, user-profile paths and anything shaped like a licence key first:
- Send error diagnostics, in Settings > Privacy. It is on by default. With a licence key entered, new lines are uploaded two minutes after start and then every six hours. Without a key, nothing is uploaded. The server keeps them for 90 days.
- A report you send yourself: the Report a Problem card in Settings, or the crash prompt w0a shows after a failure, which asks first.
Turn the switch off and the file goes nowhere unless you send it.
Size and deleting it
The file is kept under 512 KB. When it grows past that, w0a cuts it down to the newest 200 lines.
You can delete it at any time; w0a starts a new one with the next line. The numbering carries on from where it was, so a line already uploaded is not sent again.
Sending it
If it is long, do not paste the whole file. The last 120 lines are almost always the relevant part, because the newest entries are at the bottom. The Report a Problem card sends exactly those 120 lines when Attach the error log (recommended) is ticked.
The other files in the folder
The same folder holds a few more files. Each answers one question, and none of them is uploaded:
| File | What it answers |
|---|---|
startup-trace.log | How far the last start got, step by step. Rewritten on every launch. |
game.log | When a game was seen starting and stopping. |
engine.log | What the background engines did, one line per finished action. |
perf.log | Moments the w0a window was slow to draw, and what the core reserve engine cost during a game. |
crashstate.json | Whether the last run closed cleanly; the safe-mode crash count is kept here. |
engine.log and game.log contain program names, which is why they stay local. If a problem is about a game feeling different with the engines on, engine.log is the file to look at first.
Related
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