Fix the FS2004 logbook error on exit by repairing the FS9.cfg LOG_FILE path, replacing a corrupt logbook, and checking write permissions.
To fix a logbook error when exiting FS2004, close the simulator, back up FS9.cfg, then correct its [LOGBOOK] LOG_FILE entry so it points to a valid, writable logbook.log file. If the file itself is corrupt, rename it and let FS2004 create a fresh logbook instead.
How do I correct the FS2004 LOG_FILE entry?
- Close FS2004 completely. Do not edit FS9.cfg while
fs9.exeis running, because the simulator may overwrite the change when it exits. - Find FS9.cfg. On modern Windows installations, press Windows key + R and enter
%APPDATA%\Microsoft\FS9. Our guide to locating FS9.cfg on modern Windows covers hidden folders and filename extensions. - Make a backup. Copy FS9.cfg somewhere safe before opening it in a plain-text editor. If this is your first configuration edit, follow our safe FS9.cfg backup and editing advice.
- Find the logbook section. Search for
[LOGBOOK]and inspect the line beginningLOG_FILE=. A copied configuration may still reference an old Windows account or an obsoleteC:\Documents and Settingspath. - Enter a valid absolute path. A typical entry is shown below, but substitute the real location and Windows account name on your PC.
[LOGBOOK]
LOG_FILE=C:\Users\YourName\Documents\Flight Simulator Files\logbook.log
The folder must already exist and be writable. If Documents is redirected through OneDrive, use its actual local path. Alternatively, create a simple user-owned folder such as C:\Users\YourName\FS9Data and point LOG_FILE there. Do not copy the example literally, add quotation marks or leave more than one LOG_FILE entry.
- Save and test. Start FS2004, load and end a short flight, then exit the simulator. Confirm that the error has gone and that
logbook.loghas been created or updated.
Which logbook fix matches the symptom?
| What you find | Likely cause | Correct action |
|---|---|---|
| The path names an old user account or missing folder | Broken LOG_FILE reference | Point it to an existing writable folder |
| The path is valid, but a fresh logbook works | Corrupt logbook.log | Keep the old file as a backup and use the new one |
| You cannot create a test file in the target folder | Windows permissions or security protection | Choose a user-owned folder or allow FS2004 to write there |
| The FS9.cfg change disappears | FS2004 was open, or FS9.cfg is read-only | Close FS2004, clear read-only temporarily and edit again |
What if logbook.log itself is corrupt?
A damaged logbook must be separated from the path problem. Close FS2004, locate the file specified by LOG_FILE, copy it as a backup, then rename it to something such as logbook.log.old.
Start FS2004 and let it create a new logbook.log when it next records an entry. Your previous flight history will not appear in the fresh file. Do not open and resave the old file as ordinary text merely because it uses a .log extension; that can make the damage worse.
Why does the logbook error return after editing FS9.cfg?
The error usually returns because FS2004 still cannot write to the selected location. Check that neither FS9.cfg nor logbook.log is marked read-only, and test whether you can create and delete a small text file in the target folder.
Windows security features can block an older program from writing to protected Documents folders. Allow fs9.exe through the relevant protection rather than disabling security globally. Moving the logbook to a simple folder inside your user profile is often cleaner than running FS2004 permanently as administrator.
Should I rebuild FS9.cfg?
Rebuild FS9.cfg only if correcting LOG_FILE, replacing the logbook and checking permissions do not work. With FS2004 closed, rename FS9.cfg to FS9.cfg.old, start the simulator and allow it to generate a default configuration.
This resets simulator preferences, so retain the backup and reapply settings selectively. Our broader FS2004 configuration-reset procedure explains the same fallback and the checks to make before restoring an old configuration wholesale.