Package seems not to work

[aukselis-c1connections]

🔍 Before submitting the issue

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

🐞 Description of the bug

I am using a clean setup of a virtual environment with only PyMechanical installed. However by running a simple example, I get the following error.

WARNING -  -  initializer - _get_latest_default_version - Multiple versions of Mechanical found! Using latest version 251 ...
legacy Provider loading failed 
EVP_DecryptInit. could not load the shared library

What am I doing wrong?

📝 Steps to reproduce

from ansys.mechanical.core import App
app = App()
app.update_globals(globals())
print(app)

💻 Which operating system are you using?

Windows

📀 Which ANSYS version are you using?

2025R1

🐍 Which Python version are you using?

3.12

📦 Installed packages

here is my installed packages:

nsys-api-mechanical==0.1.2
ansys-mechanical-core==0.11.14
ansys-mechanical-env==0.1.9
ansys-mechanical-stubs==0.1.6
ansys-pythonnet==3.1.0rc6
ansys-tools-path==0.7.1
appdirs==1.4.4
certifi==2025.1.31
cffi==1.17.1
charset-normalizer==3.4.1
click==8.1.8
clr-loader==0.2.7.post0
colorama==0.4.6
grpcio==1.71.0
idna==3.10
importlib-metadata==8.6.1
platformdirs==4.3.7
protobuf==5.29.4
psutil==7.0.0
pycparser==2.22
requests==2.32.3
tqdm==4.67.1
urllib3==2.4.0
zipp==3.21.0

[koubaa]

This seems related to #1136

Could you please enable logging as shown in this comment and share the output?

[aukselis-c1connections]

Thanks for taking a look at the issue. Here is the output shown when running your suggested lines. I have changed 242 to 251:

2025-04-22 09:16:03.934707 (Thread 0x00001ea0) [PYMECHANICAL, info] ------------ : Initialize pythonnet interop handling
2025-04-22 09:16:07.232099 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : Checking debug stop
2025-04-22 09:16:07.233083 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : using aisolPath C:\Program Files\ANSYS Inc\v251\aisol\bin\winx64
2025-04-22 09:16:07.233083 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : Setting environment
2025-04-22 09:16:07.988531 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : running wb config
2025-04-22 09:16:08.017933 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : running AnsCoInitialize
2025-04-22 09:16:08.487873 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : ran AnsCoInitialize, result: 1
2025-04-22 09:16:08.488876 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : ran AnsSetRegistryLoadConfiguration, result: 0
2025-04-22 09:16:08.526228 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : Installing CLRHost
2025-04-22 09:16:08.668286 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : AnsCLRHostManagedLite::AnsCLRHostManaged
2025-04-22 09:16:08.703444 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : Installed CLRHost
2025-04-22 09:16:08.703444 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : using dummy command line: "C:\Program Files\ANSYS Inc\v251\aisol\bin\winx64\AnsysWBU.exe"  -DSApplet -AppModeMech -b
2025-04-22 09:16:08.737087 (Thread 0x00001ea0) [EmbeddedMechanical, trace] ----- : Initializing WorkBench
2025-04-22 09:16:08.784361 (Thread 0x00001ea0) [WORKBENCH, info] --------------- : ************ Workbench 1 - version: 251 build: 20241113 ************
2025-04-22 09:16:08.785540 (Thread 0x00001ea0) [WORKBENCH, info] ----- ScopeBegin: CWB::FinalConstruct Private memory usage <82305.024 KB>
2025-04-22 09:16:08.839986 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : ActiveWBMgrObject creation succeeded
2025-04-22 09:16:08.842716 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : WBCommandLine creation succeeded
2025-04-22 09:16:08.842716 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : WBSplashScreen creation succeeded
2025-04-22 09:16:08.976452 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : Verification creation succeeded
2025-04-22 09:16:08.987190 (Thread 0x00001ea0) [DESIGNSPACE, info] --- ScopeBegin: CWBStringTable::Load C:\Program Files\ANSYS Inc\v251\AISOL\CommonFiles\CommonPages\Language\en-us\xml\commonStringTable.xml Private memory usage <82763.776 KB>
2025-04-22 09:16:08.988558 (Thread 0x00001ea0) [DESIGNSPACE, info] --- ScopeEnd  : CWBStringTable::Load C:\Program Files\ANSYS Inc\v251\AISOL\CommonFiles\CommonPages\Language\en-us\xml\commonStringTable.xml Private memory usage <83136.512 KB> (delta <372.736 KB>), Peak working set size <120291.328 KB>, Elapsed <1 ms>
2025-04-22 09:16:09.279392 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : PartMgr creation succeeded
2025-04-22 09:16:09.291756 (Thread 0x00001ea0) [DESIGNSPACE, info] --- ScopeBegin: CWBStringTable::Load C:\Program Files\ANSYS Inc\v251\AISOL\CADIntegration\CIPages\Language\en-us\xml\PMStringTable.xml Private memory usage <87924.736 KB>
2025-04-22 09:16:09.295100 (Thread 0x00001ea0) [DESIGNSPACE, info] --- ScopeEnd  : CWBStringTable::Load C:\Program Files\ANSYS Inc\v251\AISOL\CADIntegration\CIPages\Language\en-us\xml\PMStringTable.xml Private memory usage <88268.800 KB> (delta <344.064 KB>), Peak working set size <124289.024 KB>, Elapsed <2 ms>
2025-04-22 09:16:09.295100 (Thread 0x00001ea0) [DESIGNSPACE, trace] ------------ : CWBStringTable::put_Locale:en-us
2025-04-22 09:16:09.461018 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : WBSession creation succeeded
2025-04-22 09:16:09.505086 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : CWB - PreferenceManager creation succeeded
2025-04-22 09:16:09.509435 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : CWB - FinalConstruct succeeded
2025-04-22 09:16:09.509435 (Thread 0x00001ea0) [WORKBENCH, info] ----- ScopeEnd  : CWB::FinalConstruct Private memory usage <89231.360 KB> (delta <6926.336 KB>), Peak working set size <125845.504 KB>, Elapsed <723 ms>
2025-04-22 09:16:09.511069 (Thread 0x00001ea0) [WORKBENCH, info] ----- ScopeBegin: CWB::Initialize before Core Loop Private memory usage <89239.552 KB>
2025-04-22 09:16:09.511069 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : "C:\Program Files\ANSYS Inc\v251\aisol\bin\winx64\AnsysWBU.exe"  -DSApplet -AppModeMech -b
2025-04-22 09:16:09.511683 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : CreateParameterManager started
2025-04-22 09:16:09.511683 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : CreateParameterManager done
2025-04-22 09:16:09.513784 (Thread 0x00001ea0) [WORKBENCH, trace] -------------- : CWB::setting startup options
2025-04-22 09:16:09.514329 (Thread 0x00001ea0) [WORKBENCH, info] ----- ScopePoint: Pre CWB::Run Initialize Complete
2025-04-22 09:16:09.514329 (Thread 0x00001ea0) [WORKBENCH, info] ----- ScopeBegin: CWB::Run Private memory usage <89239.552 KB>
2025-04-22 09:16:09.514874 (Thread 0x00001ea0) [WORKBENCH, info] ----- ScopeBegin: Pre Applet Initialization Tasks Private memory usage <89239.552 KB>
2025-04-22 09:16:09.514874 (Thread 0x00001ea0) [WORKBENCH, info] ----- ScopeBegin: Initialize Permit Boss Private memory usage <89239.552 KB>
legacy Provider loading failed
EVP_DecryptInit. could not load the shared library
2025-04-22 09:16:09.857339 (Thread 0x00001dbc) [WORKBENCH, trace] -------------- : AnsCLRHostManagedLite::~AnsCLRHostManaged

[aukselis-c1connections]

I found the issue. I am using uv package manager. Python distributions downloaded by this package manager have libcrypto-3.dll and libssl-3.dll located in the distribution DLLs folder named as libcrypto-3-x64.dll and libssl-3-x64.dll respectively. Renaming them to libcrypto-3.dll and libssl-3.dll solved the issue.

Perhaps the package could be updated to look for alternative names, if possible also.

[aukselis-c1connections]

Hmm, renaming the files makes PyMechanical happy but breaks SSL library in Python so
python -c "import ssl; print(ssl.OPENSSL_VERSION)" does not work anymore. So it's not a solution

[koubaa]

@aukselis-c1connections interesting - I didn't know that any python distribution customizes SSL.

@RobPasMue @MaxJPRey Do you know much about the uv package manager and potential limitations with the rest of the pyansys ecosystem? It's my first hearing about it.

[aukselis-c1connections]

@aukselis-c1connections interesting - I didn't know that any python distributions customize SSL.

I do not think it customises it. It appears that adding -x86 or -x64 is a completely valid naming convention. Not sure how the files themselves compare and if they are the same, other than the name.

We are using the uv package manager and many products from the PyAnsys ecosystem, and this is the first one that we have had this issue with.

[koubaa]

@aukselis-c1connections

I don't have a problem with the naming convention. By customize I mean that for SLL, uv's distribution differs in some observable way from the CPython.

In the case of DLL names, the windows library loader prevents loading multiple libraries with the same name into the same process. We happen to distribute a libcrypto-3-x64.dll and libssl-3-x64.dll with Mechanical.

If the libraries have different filenames, then the windows OS will happily let python load libssl-3.dll and mechanical load libssl-3-x64.dll all in the same process. However, when they use the same name, and the versions* of these SSL DLLS are different between Mechanical and Python, and the runtime behavior is affected by these differences, you will see a problem.

*The version number "3" in the DLL name only indicates the major version of SSL, and indeed they could be different minor or patch versions.

[aukselis-c1connections]

Clear. Here is more information

Latest Python 3.12 version from python.org (where PyMechnical works):
3.12.10 (tags/v3.12.10:0cc8128, Apr  8 2025, 12:21:36) [MSC v.1943 64 bit (AMD64)]
SSL: OpenSSL 3.0.16 11 Feb 2025 [python -c "import ssl; print(ssl.OPENSSL_VERSION)"]
     libssl-3.dll size 936 448 bytes
     libcrypto-3.dll size 5 932 032 bytes

Latest Python 3.12 managed by uv (where PyMechanical does not work)
3.12.10 (main, Apr  9 2025, 04:06:22) [MSC v.1943 64 bit (AMD64)]
SSL: OpenSSL 3.0.16 11 Feb 2025 [python -c "import ssl; print(ssl.OPENSSL_VERSION)"]
     libssl-3-x64.dll size 794 992 bytes
     libcrypto-3-x64.dll size 5 231 472 bytes

Versions appear to be the same, however, the size differs. Hope this helps.

[RobPasMue]

I didn't know that any python distribution customizes SSL.

@RobPasMue @MaxJPRey Do you know much about the uv package manager and potential limitations with the rest of the pyansys ecosystem? It's my first hearing about it.

I am not aware of any issues with UV and other packages. Some teams have been using it already for development. Those DLLs are definitely not the same (according to their size)... However, I am not surprised "python -c "import ssl; print(ssl.OPENSSL_VERSION)" does not work... they might be expecting a certain name convention for their DLL when performing that operation (and the way they link to the underlying dll)

[aukselis-c1connections]

Okay, so upon further investigation, PyMechanical (v251) expects OpenSSL 3.0.14 with file names libssl-3-x64.dll and libcrypto-3-x64.dll. If another dll with that file name is available in the user path, it takes it. So, in case of UV, it takes UV's OpenSSL library, version 3.0.16, and gets stuck on it. In case of regular Python, because OpenSSL DLLs have different file names, it takes its own DLLs, and it works.

Not sure why a point release breaks compatibility (Perhaps it's simply how they are compiled and linked, and the issue is not a version). But perhaps, PyMechanical can always load its own DLLs, regardless what is the path.

[koubaa]

After some research, I summarized my findings in this issue that I filed to the uv package manager code which builds the python executable for distribution.

cc @RobPasMue @dipinknair @MaxJPRey

[RobPasMue]

Thanks for opening the issue @koubaa