Windows app not launching

[uttkarsh-thakur26]

When launching the Windows .exe version of the app, it crashes immediately with a database-related exception.

The error indicates that a column (users.is_verified) does not exist in the SQLite database, causing the application to fail during execution.

Steps to reproduce

1. Launch the Windows .exe application
2. App crashes immediately with the above error

Environment

• App source: EXE (Windows app)
• App version: v4.0
• OS: Windows

[uttkarsh-thakur26]

Tried to run it as an admin but this happened...

[uttkarsh-thakur26]

I have found a fix for this

It appears the database migration fails because it attempts to modify a table (artifacts) that is missing from the local SQLite schema in older versions.

How to Fix

The most reliable solution is to delete the local database file and let the application regenerate a fresh, up-to-date schema.

Note: This will reset your local crawl history and settings.

1. Locate the database file: %AppData%\LNCrawl\sqlite.db
2. Delete it via PowerShell:

   Remove-Item "$env:AppData\LNCrawl\sqlite.db"

3. Restart the server:

   lncrawl -ll server -p 8080

Technical Root Cause

Migrations work like a timeline. The app thought my database is at "Version A" and tries to move it to "Version B." In this case, "Version B" requires adding a column to a table called artifacts, but for some reason, "Version A" in my local file didn't actually contain that table. This mismatch causes SQLAlchemy/Alembic to crash.
Before this I was using the older version of the application, I think that's why this happened.

[sebbu2]

@uttkarsh-thakur26 your solution doesn't work for me:

Failed to execute script '__main__' due to unhandled exception:
Unable to configure formatter 'default'

Traceback (most recent call last):
  File "logging\config.py", line 587, in configure
  File "logging\config.py", line 699, in configure_formatter
  File "logging\config.py", line 490, in configure_custom
  File "uvicorn\logging.py", line 42, in __init__
AttributeError: 'NoneType' object has no attribute 'isatty'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "__main__.py", line 16, in <module>
  File "lncrawl\__init__.py", line 33, in main
    app()
  File "typer\main.py", line 1152, in __call__
  File "typer\main.py", line 1135, in __call__
  File "click\core.py", line 1485, in __call__
  File "typer\core.py", line 795, in main
  File "typer\core.py", line 188, in _main
  File "click\core.py", line 1873, in invoke
  File "click\core.py", line 1269, in invoke
  File "click\core.py", line 824, in invoke
  File "typer\main.py", line 1514, in wrapper
  File "lncrawl\commands\server.py", line 29, in server
    uvicorn.run(
  File "uvicorn\main.py", line 541, in run
  File "uvicorn\config.py", line 280, in __init__
  File "uvicorn\config.py", line 372, in configure_logging
  File "logging\config.py", line 942, in dictConfig
  File "logging\config.py", line 590, in configure
ValueError: Unable to configure formatter 'default'

[zforma]

I have the same problem. Nothing helps.

[uttkarsh-thakur26]

@sebbu2
The error seems to be related to terminal supporting colored logs, it cannot find a valid standard output (stdout). This often happens when running in certain IDE terminals, non-interactive shells, or as a background service.

Suggested Workarounds

1. Use a standard Terminal/PowerShell
If you are running this inside an IDE (like VS Code or PyCharm) or a specialized shell, try running it in a standard Windows PowerShell or Command Prompt window instead.

2. Force Python Unbuffered Mode
You can try setting an environment variable to force Python to handle I/O differently. Run this in your PowerShell before starting the server:

$env:PYTHONUNBUFFERED=1
lncrawl -ll server -p 8080

[uttkarsh-thakur26]

@zforma

sqlite3.OperationalError

This error confirms that your local database schema is out of sync with the current version of the app. Specifically, your users table is missing the is_verified column required by the new update.

Even if you've tried other fixes, a complete database reset is the only way to ensure the schema is built correctly from scratch.

Try this:

1. Close LNCrawl completely. Ensure no background processes are running in Task Manager.
2. Delete the database file. Open PowerShell and run:

   Remove-Item "$env:AppData\LNCrawl\sqlite.db" -ErrorAction SilentlyContinue

   If you get an "Access Denied" error, the app is still running. Close it and try again.
3. Restart the application. LNCrawl will detect the missing file and generate a fresh sqlite.db containing all the correct tables and columns.

This is happening because the application skips a migration step during an update. By deleting the .db file, you force the app to run its bootstrap() sequence, which builds the entire database.

@dipu-bd You can add a Reset Database button, it would save a lot of users from having to hunt through their AppData folders!

[Konkreciarz]

You keep mentioning:

AppData\LNCrawl\sqlite.db

but my files are located at:

AppData\Roaming\LNCrawl

and deleting them doesn't work anyways

[MaraSkywalker]

I have the same problem but know nothing about fixing it myself. Would it be possible to release a new version of the windows exe version where this is fixed? Thank you!

[uttkarsh-thakur26]

Yeah, they need to do "Regression Testing" before pushing an update.(Still I am thankful for this app)
@dipu-bd

[sebbu2]

Deleting the .db doesn't work

[multiglobal68-max]

Same here even with today version V4.2.1

127.0.0.1 refused to connect.

[dipu-bd]

It's a good idea to reset database in case of failure. I will check if it's possible to add it.

Generally, deleting the LNCrawl or .lncrawl folder would help.

You can also change the database url with lncrawl config