## What this teaches

How to (trapped) error reading bcrypt version.

## The problem

Issue langflow-ai/langflow#1173 (closed, 21 comments): **Describe the bug** Trying to start langflow using the "python -m langflow" command after installing it in a conda environment on Windows 10 x64 results in the following error message: [image] ``` [12/04/23 17:49:31] INFO 2023-12-04 17:49:31 - INFO - manager - Alembic not initialized manager.py:140 INFO 2023-12-04 17:49:31 - INFO - manager - Initializing alembic manager.py:121 INFO 2023-12-04 17:49:31 - INFO - manager - Alembic initialized manager.py:126 INFO 2023-12-04 17:49:31 - INFO - manager - Running DB migrations in manager.py:149 [the user's home directory]

## What worked (verified answer)

If starting langflow fails with '(trapped) error reading bcrypt version', it is a passlib/bcrypt version incompatibility, not your code. Pin bcrypt to 4.0.1 (with passlib 1.7.4), which the maintainer and multiple users confirmed resolves it.

## Source

gh:langflow-ai/langflow#1173 - https://github.com/langflow-ai/langflow/issues/1173