--- id: SAIFTRBL0007 moved_from: - guides/troubleshooting/function-app-deploy-invalid-version-runtime-warning.md title: Function App deploy warns "Invalid version" for runtime and then times out description: A cosmetic runtime-version warning during Azure Function App zip deploy is often followed by a 504 gateway timeout; retrying the pipeline usually succeeds, and the version should not be changed to silence the warning. tags: - troubleshooting - pipelines --- # Function App deploy warns "Invalid version" for runtime and then times out **One-sentence summary:** the `Invalid version` warning during `az functionapp` zip deploy is unrelated to the deploy failure — a 504 gateway timeout on the zip deploy step is the real cause, and a pipeline re-run is the fix. --- ## 🚨 Symptom A Function App deployment pipeline (for example `policyportal-sub` deploying to production) fails with: ```text WARNING: Invalid version: 10.0 for runtime dotnet-isolated and os linux. Supported versions for runtime dotnet-isolated and os linux are: ['10', '9', '8', '7', '6']. Run 'az functionapp list-runtimes' for more details on supported runtimes. WARNING: Getting scm site credentials for zip deployment WARNING: Starting zip deployment. This operation can take a while to complete ... WARNING: Deployment endpoint responded with status code 504 ERROR: An error occured during deployment. Status Code: 504, Details: 504.0 GatewayTimeout ❌ Zip deployment to Function App production (no slot) failed with exit code: 1 ``` Appears in Azure DevOps pipeline logs during the "Zip deployment" step of a Function App release. --- ## 📌 Applies to | Aspect | Value | | ------ | ----- | | **Component** | Azure DevOps pipelines, Azure Function App deployment (`az functionapp` / `AzureFunctionApp@1`) | | **Forge versions** | Any pipeline deploying a `dotnet-isolated` Function App on Linux | | **Related versions** | Seen with a `10.0` runtime version configured; the warning also appears with other decimal versions | --- ## 🧠 Cause Two separate things happen in the same log and are easy to conflate: 1. The `Invalid version` line is a **cosmetic warning**. The Azure CLI expects a whole-number runtime version (`10`, `9`, `8`, `7`, `6`) and rejects the decimal form (`10.0`) used in configuration, but this does not fail the deployment by itself. Changing the configured version to a non-decimal value to silence the warning has caused the zip deploy to *report* success while the Function App silently fails to start — reverting to the decimal version restored a working deploy. Do not "fix" the version to make the warning go away. 2. The actual failure is a **504 Gateway Timeout** on the zip deployment endpoint, which is typically a transient timeout, not a configuration problem. Re-running the pipeline has resolved it without any other change. --- ## ✅ Fix 1. Re-run (retry) the failed pipeline stage/build. No configuration change is needed. ```text Azure DevOps → Pipeline run → Rerun failed jobs ``` 2. If retries fail repeatedly (not just an occasional timeout), escalate — automatic pipeline retries for this case have been considered but not yet implemented, as manual retries are infrequent. Do not change the configured runtime version from its decimal form (e.g. `10.0`) to a non-decimal value (e.g. `10`) solely to suppress the `Invalid version` warning — this has been tried and caused the Function App to fail to start after an apparently successful zip deploy. --- ## 🔬 Verify The pipeline's zip deployment step completes without a 504, and the Function App production slot is reachable and serving requests after the run. --- ## 📚 Related - Azure DevOps build: