"_InterpolationType" is already registered! with matplotlib=3.10.5

[bollerdominik]

Hi I noticed all my new ComfyUI instances are failing when using IPAdapter FaceId Plus v2

After a lot of digging I was able to drill down the issue to matplotlib. With matplotlib=3.10.5 (released 31.7.2025) it does not work

With the previous version matplotlib=3.10.3 it works. Downgrading matplotlib manually in ComfyUI resolved the issue

[cubiq]

please post the full backtrace of the error from the console

[bollerdominik]

!!! Exception during processing !!! generic_type: type "_InterpolationType" is already registered!
Traceback (most recent call last):
  File "/workspace/ComfyUI/custom_nodes/ComfyUI_IPAdapter_plus/utils.py", line 159, in insightface_loader
    from insightface.app import FaceAnalysis
  File "/opt/environments/python/comfyui/lib/python3.10/site-packages/insightface/init.py", line 18, in <module>
    from . import app
  File "/opt/environments/python/comfyui/lib/python3.10/site-packages/insightface/app/init.py", line 2, in <module>
    from .mask_renderer import *
  File "/opt/environments/python/comfyui/lib/python3.10/site-packages/insightface/app/mask_renderer.py", line 8, in <module>
    from ..thirdparty import face3d
  File "/opt/environments/python/comfyui/lib/python3.10/site-packages/insightface/thirdparty/face3d/init.py", line 3, in <module>
    from . import mesh
  File "/opt/environments/python/comfyui/lib/python3.10/site-packages/insightface/thirdparty/face3d/mesh/init.py", line 11, in <module>
    from . import vis
  File "/opt/environments/python/comfyui/lib/python3.10/site-packages/insightface/thirdparty/face3d/mesh/vis.py", line 6, in <module>
    import matplotlib.pyplot as plt
  File "/opt/environments/python/comfyui/lib/python3.10/site-packages/matplotlib/init.py", line 161, in <module>
    from . import *api, *version, cbook, _docstring, rcsetup
  File "/opt/environments/python/comfyui/lib/python3.10/site-packages/matplotlib/rcsetup.py", line 28, in <module>
    from matplotlib.colors import Colormap, is_color_like
  File "/opt/environments/python/comfyui/lib/python3.10/site-packages/matplotlib/colors.py", line 57, in <module>
    from matplotlib import *api, *cm, cbook, scale, _image
ImportError: generic_type: type "_InterpolationType" is already registered!
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/workspace/ComfyUI/execution.py", line 496, in execute
    output_data, output_ui, has_subgraph, has_pending_tasks = await get_output_data(prompt_id, unique_id, obj, input_data_all, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb, hidden_inputs=hidden_inputs)
  File "/workspace/ComfyUI/execution.py", line 315, in get_output_data
    return_values = await asyncmap_node_over_list(prompt_id, unique_id, obj, input_data_all, obj.FUNCTION, allow_interrupt=True, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb, hidden_inputs=hidden_inputs)
  File "/workspace/ComfyUI/execution.py", line 289, in asyncmap_node_over_list
    await process_inputs(input_dict, i)
  File "/workspace/ComfyUI/execution.py", line 277, in process_inputs
    result = f(**inputs)
  File "/workspace/ComfyUI/custom_nodes/ComfyUI_IPAdapter_plus/IPAdapterPlus.py", line 636, in load_models
    self.insightface['model'] = insightface_loader(provider)
  File "/workspace/ComfyUI/custom_nodes/ComfyUI_IPAdapter_plus/utils.py", line 161, in insightface_loader
    raise Exception(e)
Exception: generic_type: type "_InterpolationType" is already registered!

[cubiq]

it seems a problem with insightface actually (as always)

[bollerdominik]

I spend many hours today debugging this. Re-installing all nodes, insightface, opencv etc.

Only after downgrading matplotlib it worked again. Not sure where exactly the root cause is but for sure it is related to matplotlib. The issues started exactly on 31.7 when 3.10.5 was released

[cubiq]

it's a dependency issue caused by insightface