App Service Deployment Failure: Platform 'python' version '3.11' is unsupported

Question

We are experiencing a sudden deployment failure for our Streamlit application on Azure App Service (Linux). While deployments were successful as of March 25, 2026, attempts on March 30, 2026, are failing during the Oryx build process.

Environment:

• Local IDE: Visual Studio Code (Azure Extension)
• App Service Runtime: Python 3.11
• OS Type: Bullseye

The Error: Despite the App Service being configured for Python 3.11, the Oryx build engine returns the following error: Error: Platform 'python' version '3.11' is unsupported. Supported versions: 3.10.0 ... 3.10.19

Logs:

Command: oryx build /tmp/zipdeploy/extracted -o /home/site/wwwroot --platform python --platform-version 3.11 -p virtualenv_name=antenv --log-file /tmp/build-debug.log  -i /tmp/8de8e4ac8a0482c --compress-destination-dir | tee /tmp/oryx-build.log
Operation performed by Microsoft Oryx, https://github.com/Microsoft/Oryx
You can report issues at https://github.com/Microsoft/Oryx/issues
Oryx Version: 0.2.20260204.1+0fdbe200b286be083841ff7fa201c6c2316dc6b9, Commit: 0fdbe200b286be083841ff7fa201c6c2316dc6b9, ReleaseTagName: 20260204.1
Build Operation ID: 0ce8b3cd192ddc60
Repository Commit : e8ee19d9-c081-4a62-9ed2-2e69ea7c07a5
OS Type           : bullseye
Image Type        : githubactions
Primary SDK Storage URL: https://oryx-cdn.microsoft.io
Backup SDK Storage URL: 
Detecting platforms...
External SDK provider is enabled.
Requesting metadata for platform python from external SDK provider
Requesting metadata for platform python from external SDK provider
Error: Platform 'python' version '3.11' is unsupported. Supported versions: 3.10.0, 3.10.0a2, 3.10.13, 3.10.14, 3.10.15, 3.10.16, 3.10.17, 3.10.18, 3.10.19
Error: Platform 'python' version '3.11' is unsupported. Supported versions: 3.10.0, 3.10.0a2, 3.10.13, 3.10.14, 3.10.15, 3.10.16, 3.10.17, 3.10.18, 3.10.19\n/bin/bash -c "oryx build /tmp/zipdeploy/extracted -o /home/site/wwwroot --platform python --platform-version 3.11 -p virtualenv_name=antenv --log-file /tmp/build-debug.log  -i /tmp/8de8e4ac8a0482c --compress-destination-dir | tee /tmp/oryx-build.log ; exit $PIPESTATUS "

Questions:

1. Regression Check: Has there been a recent update to the Oryx build image (Release 20260204.1) that deprecated Python 3.11 support or changed the SDK metadata URL?
2. Environment Variable Fix: Is there a specific App Setting we can toggle to force the use of the correct SDK?
3. Manual Override: How can we bypass the "External SDK provider" if it is failing to fetch the Python 3.11 metadata?
4. Workaround: If this is a known bug, is there a recommended temporary configuration that won't break Streamlit dependencies?

Answer 1

Hii @Vishal Bhalabar

Thank you for reporting the issue. The deployment failures you experienced were caused by a platform‑side incident affecting Oryx‑based Python builds on Linux App Service, impacted the Oryx External SDK Provider, which is responsible for resolving available Python versions during build time.

During the incident window, the external provider incorrectly returned only Python 3.10.x SDKs, while Python 3.11+ (including 3.12) were temporarily missing.

Temporary workaround (no longer required):

• During the incident, the following workaround was used to bypass the faulty provider:

  ORYX_ENABLE_EXTERNAL_SDK_PROVIDER=false

If this setting was added temporarily, we recommend removing it now that the platform fix is in place, so your app continues using the standard, supported SDK resolution path.

• No customer action required
• No changes are needed to your App Service runtime, app settings, or deployment workflow.
  • This issue was not caused by your configuration or deployment process.

Kindly let us know if the above helps or you need further assistance on this issue.

Please "accept" if the information helped you. This will help us and others in the community as well.