Sleap 1.5.1 on Windows 11 bug with skeleton

[johnleeuk12]

Bug description

AttributeError: 'list' object has no attribute 'nodes'

If I create any kind of skeleton (even without edges) regardless of name changes, it seems that the variable "skeleton" has no attribute called nodes.
I cannot load any other skeletons, regardless of which sleap version they were saved in.

Expected behaviour

When I press Load skeleton, I expect it to load the skeleton

Actual behaviour

AttributeError: 'list' object has no attribute 'nodes'

Then, I can't create any new nodes because the following error happens:
AttributeError: 'list' object has no attribute 'add_node'

Your personal set up

• OS: Windows 11

• Version(s):

• SLEAP installation method (listed here):
  Sleap 1.5.1 I tried both CUDA and CPU only versions, installed through conda and pip

Environment packages

aiohappyeyeballs             2.6.1            pypi_0              pypi
aiohttp                      3.13.1           pypi_0              pypi
aiosignal                    1.4.0            pypi_0              pypi
albucore                     0.0.24           pypi_0              pypi
albumentations               2.0.8            pypi_0              pypi
annotated-types              0.7.0            pypi_0              pypi
antlr4-python3-runtime       4.9.3            pypi_0              pypi
anyio                        4.11.0           pypi_0              pypi
argon2-cffi                  25.1.0           pypi_0              pypi
argon2-cffi-bindings         25.1.0           pypi_0              pypi
arrow                        1.4.0            pypi_0              pypi
asttokens                    3.0.0            pypi_0              pypi
async-lru                    2.0.5            pypi_0              pypi
attrs                        25.4.0           pypi_0              pypi
av                           15.1.0           pypi_0              pypi
babel                        2.17.0           pypi_0              pypi
beautifulsoup4               4.14.2           pypi_0              pypi
bleach                       6.2.0            pypi_0              pypi
bzip2                        1.0.8            h0ad9c76_8          conda-forge
ca-certificates              2025.10.5        h4c7d964_0          conda-forge
cattrs                       25.3.0           pypi_0              pypi
certifi                      2025.10.5        pypi_0              pypi
cffi                         2.0.0            pypi_0              pypi
charset-normalizer           3.4.4            pypi_0              pypi
click                        8.3.0            pypi_0              pypi
colorama                     0.4.6            pypi_0              pypi
comm                         0.2.3            pypi_0              pypi
contourpy                    1.3.3            pypi_0              pypi
cycler                       0.12.1           pypi_0              pypi
debugpy                      1.8.17           pypi_0              pypi
decorator                    5.2.1            pypi_0              pypi
defusedxml                   0.7.1            pypi_0              pypi
executing                    2.2.1            pypi_0              pypi
fastjsonschema               2.21.2           pypi_0              pypi
filelock                     3.20.0           pypi_0              pypi
fonttools                    4.60.1           pypi_0              pypi
fqdn                         1.5.1            pypi_0              pypi
frozenlist                   1.8.0            pypi_0              pypi
fsspec                       2025.9.0         pypi_0              pypi
gitdb                        4.0.12           pypi_0              pypi
gitpython                    3.1.45           pypi_0              pypi
h11                          0.16.0           pypi_0              pypi
h5py                         3.15.1           pypi_0              pypi
hdmf                         4.1.0            pypi_0              pypi
httpcore                     1.0.9            pypi_0              pypi
httpx                        0.28.1           pypi_0              pypi
hydra-core                   1.3.2            pypi_0              pypi
idna                         3.11             pypi_0              pypi
imageio                      2.37.0           pypi_0              pypi
imageio-ffmpeg               0.6.0            pypi_0              pypi
imgstore                     0.3.7            pypi_0              pypi
ipykernel                    7.0.1            pypi_0              pypi
ipython                      9.6.0            pypi_0              pypi
ipython-pygments-lexers      1.1.1            pypi_0              pypi
ipywidgets                   8.1.7            pypi_0              pypi
isoduration                  20.11.0          pypi_0              pypi
jedi                         0.19.2           pypi_0              pypi
jinja2                       3.1.6            pypi_0              pypi
joblib                       1.5.2            pypi_0              pypi
jsmin                        3.0.1            pypi_0              pypi
json5                        0.12.1           pypi_0              pypi
jsonpickle                   4.1.1            pypi_0              pypi
jsonpointer                  3.0.0            pypi_0              pypi
jsonschema                   4.25.1           pypi_0              pypi
jsonschema-specifications    2025.9.1         pypi_0              pypi
jupyter                      1.1.1            pypi_0              pypi
jupyter-client               8.6.3            pypi_0              pypi
jupyter-console              6.6.3            pypi_0              pypi
jupyter-core                 5.9.1            pypi_0              pypi
jupyter-events               0.12.0           pypi_0              pypi
jupyter-lsp                  2.3.0            pypi_0              pypi
jupyter-server               2.17.0           pypi_0              pypi
jupyter-server-terminals     0.5.3            pypi_0              pypi
jupyterlab                   4.4.9            pypi_0              pypi
jupyterlab-pygments          0.3.0            pypi_0              pypi
jupyterlab-server            2.27.3           pypi_0              pypi
jupyterlab-widgets           3.0.15           pypi_0              pypi
kiwisolver                   1.4.9            pypi_0              pypi
kornia                       0.8.1            pypi_0              pypi
kornia-rs                    0.1.9            pypi_0              pypi
lark                         1.3.0            pypi_0              pypi
lazy-loader                  0.4              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
lightning                    2.5.5            pypi_0              pypi
lightning-utilities          0.15.2           pypi_0              pypi
loguru                       0.7.3            pypi_0              pypi
markdown-it-py               4.0.0            pypi_0              pypi
markupsafe                   3.0.3            pypi_0              pypi
matplotlib                   3.10.7           pypi_0              pypi
matplotlib-inline            0.1.7            pypi_0              pypi
mdurl                        0.1.2            pypi_0              pypi
mistune                      3.1.4            pypi_0              pypi
mpmath                       1.3.0            pypi_0              pypi
multidict                    6.7.0            pypi_0              pypi
nbclient                     0.10.2           pypi_0              pypi
nbconvert                    7.16.6           pypi_0              pypi
nbformat                     5.10.4           pypi_0              pypi
ndx-pose                     0.2.2            pypi_0              pypi
nest-asyncio                 1.6.0            pypi_0              pypi
networkx                     3.5              pypi_0              pypi
nixio                        1.5.4            pypi_0              pypi
notebook                     7.4.7            pypi_0              pypi
notebook-shim                0.2.4            pypi_0              pypi
numpy                        2.2.6            pypi_0              pypi
omegaconf                    2.3.0            pypi_0              pypi
opencv-python                4.12.0.88        pypi_0              pypi
opencv-python-headless       4.12.0.88        pypi_0              pypi
openssl                      3.5.4            h725018a_0          conda-forge
packaging                    25.0             pypi_0              pypi
pandas                       2.3.3            pypi_0              pypi
pandocfilters                1.5.1            pypi_0              pypi
parso                        0.8.5            pypi_0              pypi
pillow                       12.0.0           pypi_0              pypi
pip                          25.2             pyh8b19718_0        conda-forge
platformdirs                 4.5.0            pypi_0              pypi
prometheus-client            0.23.1           pypi_0              pypi
prompt-toolkit               3.0.52           pypi_0              pypi
propcache                    0.4.1            pypi_0              pypi
protobuf                     6.33.0           pypi_0              pypi
psutil                       7.1.1            pypi_0              pypi
pure-eval                    0.2.3            pypi_0              pypi
pycparser                    2.23             pypi_0              pypi
pydantic                     2.12.3           pypi_0              pypi
pydantic-core                2.41.4           pypi_0              pypi
pygments                     2.19.2           pypi_0              pypi
pykalman                     0.10.2           pypi_0              pypi
pymatreader                  1.1.0            pypi_0              pypi
pynwb                        3.1.2            pypi_0              pypi
pyparsing                    3.2.5            pypi_0              pypi
pyside6                      6.10.0           pypi_0              pypi
pyside6-addons               6.10.0           pypi_0              pypi
pyside6-essentials           6.10.0           pypi_0              pypi
python                       3.12.12          h30ce641_0_cpython  conda-forge
python-dateutil              2.9.0.post0      pypi_0              pypi
python-json-logger           4.0.0            pypi_0              pypi
python-rapidjson             1.21             pypi_0              pypi
pytorch-lightning            2.5.5            pypi_0              pypi
pytz                         2025.2           pypi_0              pypi
pywinpty                     3.0.2            pypi_0              pypi
pyyaml                       6.0.3            pypi_0              pypi
pyzmq                        27.1.0           pypi_0              pypi
qtpy                         2.4.3            pypi_0              pypi
referencing                  0.37.0           pypi_0              pypi
requests                     2.32.5           pypi_0              pypi
rfc3339-validator            0.1.4            pypi_0              pypi
rfc3986-validator            0.1.1            pypi_0              pypi
rfc3987-syntax               1.1.0            pypi_0              pypi
rich                         14.2.0           pypi_0              pypi
rpds-py                      0.27.1           pypi_0              pypi
ruamel-yaml                  0.18.15          pypi_0              pypi
ruamel-yaml-clib             0.2.14           pypi_0              pypi
scikit-base                  0.12.6           pypi_0              pypi
scikit-image                 0.25.2           pypi_0              pypi
scikit-learn                 1.7.2            pypi_0              pypi
scipy                        1.16.2           pypi_0              pypi
seaborn                      0.13.2           pypi_0              pypi
send2trash                   1.8.3            pypi_0              pypi
sentry-sdk                   2.42.1           pypi_0              pypi
setuptools                   80.9.0           pyhff2d567_0        conda-forge
shiboken6                    6.10.0           pypi_0              pypi
simplejson                   3.20.2           pypi_0              pypi
simsimd                      6.5.3            pypi_0              pypi
six                          1.17.0           pypi_0              pypi
sleap                        1.5.1            pypi_0              pypi
sleap-io                     0.5.5            pypi_0              pypi
sleap-nn                     0.0.2            pypi_0              pypi
smmap                        5.0.2            pypi_0              pypi
sniffio                      1.3.1            pypi_0              pypi
soupsieve                    2.8              pypi_0              pypi
stack-data                   0.6.3            pypi_0              pypi
stringzilla                  4.2.1            pypi_0              pypi
sympy                        1.14.0           pypi_0              pypi
terminado                    0.18.1           pypi_0              pypi
threadpoolctl                3.6.0            pypi_0              pypi
tifffile                     2025.10.16       pypi_0              pypi
tinycss2                     1.4.0            pypi_0              pypi
tk                           8.6.13           h2c6b04d_2          conda-forge
torch                        2.9.0+cpu        pypi_0              pypi
torchmetrics                 1.8.2            pypi_0              pypi
torchvision                  0.24.0+cpu       pypi_0              pypi
tornado                      6.5.2            pypi_0              pypi
tqdm                         4.67.1           pypi_0              pypi
traitlets                    5.14.3           pypi_0              pypi
typing-extensions            4.15.0           pypi_0              pypi
typing-inspection            0.4.2            pypi_0              pypi
tzdata                       2025.2           pypi_0              pypi
tzlocal                      5.3.1            pypi_0              pypi
ucrt                         10.0.26100.0     h57928b3_0          conda-forge
uri-template                 1.3.0            pypi_0              pypi
urllib3                      2.5.0            pypi_0              pypi
vc                           14.3             h2b53caa_32         conda-forge
vc14_runtime                 14.44.35208      h818238b_32         conda-forge
vcomp14                      14.44.35208      h818238b_32         conda-forge
wandb                        0.22.2           pypi_0              pypi
wcwidth                      0.2.14           pypi_0              pypi
webcolors                    24.11.1          pypi_0              pypi
webencodings                 0.5.1            pypi_0              pypi
websocket-client             1.9.0            pypi_0              pypi
wheel                        0.45.1           pyhd8ed1ab_1        conda-forge
widgetsnbextension           4.0.14           pypi_0              pypi
win32-setctime               1.2.0            pypi_0              pypi
xmltodict                    1.0.2            pypi_0              pypi
yarl                         1.22.0           pypi_0              pypi

Logs

# paste relevant logs here, if any

Screenshots

How to reproduce

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4. See error

[gitttt-1234]

Hi @johnleeuk12 !

I just tested the following on a windows11 computer (python 3.12; tested with both uv and conda installs), and it seems to work. Were you trying any of the following?

1. Opening a slp file created in an older sleap version
2. Loading a template skeleton from the GUI
3. Opening a new project and creating a new skeleton by adding nodes and edges from the GUI.

Could you share the .slp file you're trying to open here? It would be helpful to debug better from our side!

Thanks,

Divya

[johnleeuk12]

Hi Divya,

Thanks for the super fast response!

1. Yes. That one works, but it fails to load videos and I have to 1. put the raw videos in another directory and 2. change the path to those videos for SLEAP.
2. Gives the same error
3. I can add new nodes from the GUI. but the moment I save that, I can't load it. In addition, if I save the project, I cant open it with SLEAP afterwards.

I have currently rolled back to 1.4.1a2, which seems to be working, except for GPU related things.
I am currently using SLEAP just for labelling, but hope to use the training modules afterwards too.

Best,
John

[gitttt-1234]

Hi @johnleeuk12 !

I tried to open your .slp file in both old and new sleap. It doesn't seem to work (throws another error - not with skeletons), I can look into it, but I wanted to check with you because you said you were able to open the slp file in the old GUI?

Thanks,

Divya

[johnleeuk12]

Oh yeah, this one didn't open after I saved it, both on the 1.5.1 and 1.4.1a2
giving a
Keyerror: 'filename'

This was the project I created on 1.5.1, because I was able to create a new skeleton and label videos.
Once this was saved, it was impossible to open.

I also had a previous project that was made in 1.4.1a2. This one could be opened in 1.5.1 but if I saved it it wouldn't open either.
Both had the same problem of not being able to load skeletons and bugging out the moment I tried to.
It seemed that anytime I created a new project and saved it after creating a skeleton, it would no longer open.
If I create a new project (in 1.5.1) and save it before creating a skeleton, it's fine.

Thanks!

John

[gitttt-1234]

Hi @johnleeuk12 !

That's strange, I just tried to install sleap1.5 with conda+pip installation method, created a new project (added video, created new skeleton, labeled a few frames) and it seems to be working.

Does the terminal have any error logs and was it always the key error: filename issue? It seems like for some reason, the slp file didn't save the metadata associated the video files.

Thanks,

Divya

[fhj0924]

I seem to have encounte

red the same problem. Adding a new node worked the day before, but when I tried again today...

[Izumiko]

Changing this line to return skel[0] seems to work when loading the skeleton file.

sleap/sleap/gui/commands.py

Line 2304 in ed0635c

return skel

The errors AttributeError: 'list' object has no attribute 'node_names' and AttributeError: 'list' object has no attribute 'nodes' are caused by skeleton type. Expected type for "skeleton" is Skeleton, but got list[Skeleton].