write_image does not work Plotly 6.3+, Windows 10 (seemingly regardless of kaleido version) #402
Description
Hello, as discussed in this issue, for the longest time you had to use pip install kaleido==0.1.0.post1 specifically to be able to write an image otherwise it'd hang forever. In 6.3, that seems to break for a different reason:
Traceback (most recent call last):
File "C:\Users\User\projects\ftdb\test.py", line 4, in <module>
fig.write_image("figure.png")
File "C:\Users\User\Anaconda3\envs\test\lib\site-packages\plotly\basedatatypes.py", line 3895, in write_image
return pio.write_image(self, *args, **kwargs)
File "C:\Users\User\Anaconda3\envs\test\lib\site-packages\plotly\io\_kaleido.py", line 510, in write_image
img_data = to_image(
File "C:\Users\User\Anaconda3\envs\test\lib\site-packages\plotly\io\_kaleido.py", line 398, in to_image
img_bytes = scope.transform(
File "C:\Users\User\Anaconda3\envs\test\lib\site-packages\kaleido\scopes\plotly.py", line 111, in transform
raise ValueError(
ValueError: Transform failed with error code 1: Failed to serialize document: Uncaught
With upgrading to 1.0.0 I get the following error:
ERROR Thread(Thread-1 (run)) asyncio:base_events.py:default_exception_handler()- Exception in callback Broker.run_read_loop.<locals>.check_read_loop_error(<Task cancell...async.py:129>>) at C:\Users\User\Anaconda3\envs\test\lib\site-packages\choreographer\_brokers\_async.py:112
handle: <Handle Broker.run_read_loop.<locals>.check_read_loop_error(<Task cancell...async.py:129>>) at C:\Users\User\Anaconda3\envs\test\lib\site-packages\choreographer\_brokers\_async.py:112>
Traceback (most recent call last):
File "C:\Users\User\Anaconda3\envs\test\lib\asyncio\runners.py", line 44, in run
return loop.run_until_complete(main)
File "C:\Users\User\Anaconda3\envs\test\lib\asyncio\base_events.py", line 649, in run_until_complete
return future.result()
File "C:\Users\User\Anaconda3\envs\test\lib\site-packages\kaleido\__init__.py", line 54, in calc_fig
async with Kaleido(**kopts) as k:
File "C:\Users\User\Anaconda3\envs\test\lib\site-packages\choreographer\browser_async.py", line 167, in __aenter__
await self.open()
File "C:\Users\User\Anaconda3\envs\test\lib\site-packages\choreographer\browser_async.py", line 151, in open
await self.populate_targets()
File "C:\Users\User\Anaconda3\envs\test\lib\site-packages\kaleido\kaleido.py", line 181, in populate_targets
raise RuntimeError("Did you set 0 or less tabs?")
RuntimeError: Did you set 0 or less tabs?
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\User\Anaconda3\envs\test\lib\site-packages\choreographer\_brokers\_async.py", line 132, in read_loop
responses = await loop.run_in_executor(
asyncio.exceptions.CancelledError
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\User\Anaconda3\envs\test\lib\asyncio\events.py", line 80, in _run
self._context.run(self._callback, *self._args)
File "C:\Users\User\Anaconda3\envs\test\lib\site-packages\choreographer\_brokers\_async.py", line 113, in check_read_loop_error
e = result.exception()
asyncio.exceptions.CancelledError
And you can't even exit the terminal, you have to kill it from somewhere else.
Both of these on the MRE shown below, fresh conda environment with python 3.10 and just Plotly 6.3 and kaleido installed
import plotly.graph_objects as go
fig = go.Figure(data=[go.Scatter(y=[1, 3, 2])])
fig.write_image("figure.png")
# Also tried
# from kaleido import write_fig_sync
# pio.write_image(fig, "output.png")
# write_fig_sync(fig, path="figure.png")Full conda environment:
bzip2 1.0.8 h2466b09_7 conda-forge
ca-certificates 2025.8.3 h4c7d964_0 conda-forge
choreographer 1.0.10 pypi_0 pypi
kaleido 1.0.0 pypi_0 pypi
libexpat 2.7.1 hac47afa_0 conda-forge
libffi 3.4.6 h537db12_1 conda-forge
liblzma 5.8.1 h2466b09_2 conda-forge
libsqlite 3.50.4 hf5d6505_0 conda-forge
libzlib 1.3.1 h2466b09_2 conda-forge
logistro 1.1.0 pypi_0 pypi
narwhals 2.3.0 pypi_0 pypi
openssl 3.5.2 h725018a_0 conda-forge
orjson 3.11.3 pypi_0 pypi
packaging 25.0 pypi_0 pypi
pip 25.2 pyh8b19718_0 conda-forge
plotly 6.3.0 pypi_0 pypi
python 3.10.18 h8c5b53a_0_cpython conda-forge
setuptools 80.9.0 pyhff2d567_0 conda-forge
simplejson 3.20.1 pypi_0 pypi
tk 8.6.13 h2c6b04d_2 conda-forge
tzdata 2025b h78e105d_0 conda-forge
ucrt 10.0.26100.0 h57928b3_0 conda-forge
vc 14.3 h2df5915_10
vc14_runtime 14.44.35208 h818238b_31 conda-forge
vcomp14 14.44.35208 h818238b_31 conda-forge
wheel 0.45.1 pyhd8ed1ab_1 conda-forge
Let me know if I can provide any other context or if there's a known workaround.
Thank you!
Isaac