ComfyUI-Manager: No module named 'toml' (IMPORT FAILED fix)

Cannot import .../ComfyUI-Manager module for custom nodes: No module named 'toml' means Manager's automatic dependency install failed. We reproduced it with ComfyUI v0.37.0 and Manager V3.42 and fixed it.

1. The error

We started ComfyUI v0.37.0 with ComfyUI-Manager V3.42 in custom_nodes and the toml package uninstalled. Manager's prestartup script checks its own dependencies and normally installs a missing toml by itself: with network access it printed + toml==0.10.2 and loaded fine. The error only appears when that automatic install fails. We made the package index unreachable to reproduce it:

## ComfyUI-Manager: installing dependencies.
Using Python 3.11.17 environment at: /path/to/venv
error: Request failed after 3 retries in 4.0s
  cause: Failed to fetch: http://127.0.0.1:9/simple/nh3/
  cause: error sending request for url (http://127.0.0.1:9/simple/nh3/)
  cause: client error (Connect)
  cause: tcp connect error
  cause: Connection refused (os error 111)
## [ERROR] ComfyUI-Manager: Attempting to reinstall dependencies using an alternative method.
error: pip's `--user` is unsupported (use a virtual environment instead)
## [ERROR] ComfyUI-Manager: Failed to install required packages in the correct Python environment. Please install requirements.txt manually in the appropriate environment. (You can seek help at https: …
## ComfyUI-Manager: installing dependencies done.

ComfyUI then kept starting, and Manager failed to import:

[WARNING] Traceback (most recent call last):
  File "/path/to/ComfyUI/nodes.py", line 2266, in load_custom_node
    module_spec.loader.exec_module(module)
  File "<frozen importlib._bootstrap_external>", line 940, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/path/to/ComfyUI/custom_nodes/ComfyUI-Manager/__init__.py", line 12, in <module>
    import manager_server  # noqa: F401
    ^^^^^^^^^^^^^^^^^^^^^
  File "/path/to/ComfyUI/custom_nodes/ComfyUI-Manager/glob/manager_server.py", line 19, in <module>
    import manager_core as core
  File "/path/to/ComfyUI/custom_nodes/ComfyUI-Manager/glob/manager_core.py", line 26, in <module>
    import toml
ModuleNotFoundError: No module named 'toml'

[WARNING] Cannot import /path/to/ComfyUI/custom_nodes/ComfyUI-Manager module for custom nodes: No module named 'toml'

[INFO]    0.0 seconds (IMPORT FAILED): /path/to/ComfyUI/custom_nodes/ComfyUI-Manager

ComfyUI still exited 0 (other nodes loaded), so the only visible symptom is the missing Manager button. glob/manager_core.py line 26 imports toml, which is listed in Manager's own requirements.txt (not ComfyUI's).

2. Fix: install Manager's requirements.txt with ComfyUI's Python

From the ComfyUI folder, using the Python that starts ComfyUI (your venv's python; in the Windows portable build, ..\python_embeded\python.exe run from inside the ComfyUI folder):

python -m pip install -r custom_nodes/ComfyUI-Manager/requirements.txt

Collecting toml (from -r custom_nodes/ComfyUI-Manager/requirements.txt (line 9))
  Downloading toml-0.10.2-py2.py3-none-any.whl.metadata (7.1 kB)
Downloading toml-0.10.2-py2.py3-none-any.whl (16 kB)
Installing collected packages: toml
Successfully installed toml-0.10.2

On the next start, Manager loaded with no IMPORT FAILED:

[INFO]    0.0 seconds: /path/to/ComfyUI/custom_nodes/ComfyUI-Manager

If the automatic install failed for you, fix the reason too (no network, a proxy, or a Python without pip), or Manager will hit the same wall for its other dependencies. The second message above (pip's --user is unsupported) came from Manager's fallback attempt and is harmless inside a venv.

If pip says toml is already installed and the error stays, you are installing into a different Python than the one running ComfyUI. See ComfyUI: No module named 'yaml' for how to find the right one.

Related: ComfyUI-Manager: No module named 'comfy' · ComfyUI-Manager cm-cli: No module named 'utils' · ComfyUI: No module named 'numpy'

Written with AI assistance. Measured on 2026-10-24 on Linux, CPython 3.11.17, pip 26.2.2: ComfyUI v0.37.0 with ComfyUI-Manager V3.42 (commit 7e1af9c), toml uninstalled and the package index unreachable, then after pip install -r requirements.txt (toml 0.10.2). Output pasted unedited except shortened paths and long lines. PlainTables is our extension; ComfyUI, ComfyUI-Manager and toml are free.