Invalid vector subscript after DPF Vector performance improvement

[janvonrickenbach]

Before submitting the issue

• I have checked for Compatibility issues
• I have searched among the existing issues
• I am using a Python virtual environment

Description of the bug

I get the following error if I try to evaluate strains from a composite model (see script below)

ansys.dpf.gate.errors.DPFServerException: a 'data processing core error' error occurred: EPEL:155<-mapdl::rst::EPEL:176<-invalid vector subscript, failed to read elastic strains from rst file.

This has worked before 677b743 was merged.

Notes:

• I tried to make a more minimal model, but did not succeed. One observation: The script runs correctly if line 220 in ansys.dpf.composites.layup_info/_element_info.py is commented.

Steps To Reproduce

Extract the attached folder and point to it in the result_folder variable. Install pydpf-composites (pip install ansys-dpf-composites). Start a dpf server and use the correct port in the script. The problem occurs only with a grpc server (remove the port argument below to use an in-process server).

from ansys.dpf import core as dpf
grpc_server_config = dpf.AvailableServerConfigs.GrpcServer
grpc_server = dpf.start_local_server(config=grpc_server_config)
grpc_server.info

then

from ansys.dpf.composites.composite_model import CompositeModel
from ansys.dpf.composites.server_helpers import connect_to_or_start_server
from ansys.dpf.composites.data_sources import (
    get_composite_files_from_workbench_result_folder,
)

server = connect_to_or_start_server(port=50058)


result_folder = r"composites"
files = get_composite_files_from_workbench_result_folder(result_folder)
composite_model = CompositeModel(files, server=server)

composite_model.core_model.results.elastic_strain().eval()

composites.zip

Which Operating System causes the issue?

Windows

Which DPF/Ansys version are you using?

DPF Server 2025.2.pre0

Which Python version causes the issue?

3.10

Installed packages

ansys-tools-path==0.7.1
anyio==4.9.0
asyncio-atexit==1.0.1
backoff==2.2.1
certifi==2025.4.26
cfgv==3.4.0
charset-normalizer==3.4.2
click==8.1.8
colorama==0.4.6
contourpy==1.3.2
coverage==7.8.0
cycler==0.12.1
distlib==0.3.9
fast-simplification==0.1.9
fastapi==0.115.12
filelock==3.18.0
fonttools==4.57.0
grpcio==1.71.0
h11==0.16.0
httpcore==1.0.9
httpx==0.27.2
humanfriendly==10.0
humanize==4.12.3
identify==2.6.10
idna==3.10
importlib-metadata==8.7.0
iniconfig==2.1.0
jaraco-functools==4.1.0
kiwisolver==1.4.8
markdown-it-py==3.0.0
marshmallow==3.26.1
marshmallow-oneofschema==3.1.1
matplotlib==3.10.1
mdurl==0.1.2
more-itertools==10.7.0
nodeenv==1.9.1
numpy==2.2.5
packaging==25.0
pandas==2.2.3
pillow==11.2.1
platformdirs==4.3.8
plotly==5.24.1
pluggy==1.5.0
pooch==1.8.2
portend==3.2.0
pre-commit==4.2.0
protobuf==4.25.7
psutil==7.0.0
pydantic==2.11.4
pydantic-core==2.33.2
pydantic-settings==2.9.1
pygments==2.19.1
pyjwt==2.10.1
pyparsing==3.2.3
pyreadline3==3.5.4
pytest==8.3.5
pytest-asyncio==0.26.0
pytest-cov==6.1.0
pytest-rerunfailures==15.0
pytest-timeout==2.3.1
python-dateutil==2.9.0.post0
python-dotenv==1.1.0
python-multipart==0.0.20
pytz==2025.2
pyvista==0.44.2
pyyaml==6.0.2
requests==2.32.3
rich==14.0.0
scooby==0.10.1
setuptools==75.9.1
shellingham==1.5.4
six==1.17.0
sniffio==1.3.1
starlette==0.46.2
tempora==5.8.0
tenacity==9.1.2
tqdm==4.67.1
typer==0.15.3
typing-extensions==4.13.2
typing-inspection==0.4.0
tzdata==2025.2
urllib3==2.4.0
uvicorn==0.34.2
virtualenv==20.31.1
vtk==9.3.1
websockets==15.0.1
zipp==3.21.0

[janvonrickenbach]

@rafacanton @cbellot000 @FedericoNegri

[janvonrickenbach]

@roosre FYI