Recovery agent fails on every response (Microsoft.Extensions.AI version mismatch)

[akirayamamoto]

Severity

The recovery agent failed on every response, so the feature was unusable on affected builds. Fixed now, so this is for the record and the changelog.

Version

Introduced in 2026.3.2201, fixed in 2026.3.2681.

What happened?

The recovery agent threw on every response. The cause was a version mismatch in the Microsoft.Extensions.AI packages on the server.

The remote MCP endpoint (added in 2026.3.2201) pulled Microsoft.Extensions.AI.Abstractions up to 10.5.2, while the OpenAI client was still compiled against 10.5.0. 10.5.2 renamed an API the client calls, so the agent threw while parsing any reply.

Reproduction

On a build from 2026.3.2201 up to 2026.3.2680, ask the recovery agent to diagnose a failed deployment. It errors on every response.

Error and Stacktrace

System.MissingMethodException: Method not found - a member on Microsoft.Extensions.AI.Abstractions
that 10.5.2 renamed, called by the OpenAI client built against 10.5.0.

More Information

The fix pins Microsoft.Extensions.AI, .Abstractions and .OpenAI to one version so the client and the abstractions it is compiled against can't drift apart.

Workaround

Upgrade to 2026.3.2681 or later. On earlier builds there's no good workaround other than not using the recovery agent.

[akirayamamoto]

Release Note: Fixed the Recovery Agent returning an error on every response, caused by a version mismatch in its underlying AI libraries.

[team-builds-bot]

🎉 The fix for this issue has been released in:

Release stream	Release
2026.3	2026.3.2681