gemini-cli API Error: Cannot read properties of undefined (reading 'candidates')
Every request in gemini-cli 0.27.3 on Windows, using gemini-3-pro-preview and logged in with Google, fails with "API Error: Cannot read properties of undefined (reading 'candidates')" and the CLI keeps retrying the same request. The error also appears on 0.27.2 with extensions and MCPs disabled on Linux and macOS. What causes this and is there a fix?
Originally asked on GitHub: https://github.com/google-gemini/gemini-cli/issues/18621
4 answers
The issue is closed as completed, but the thread itself does not state the official root cause or a user-applied fix. What the reports show is that the error started on 2026-02-09 for many users across Windows, macOS and Linux, on gemini-cli 0.27.3 and 0.27.2, and it still happened with all extensions and MCPs disabled. One commenter speculated this might be a server-side update; another noted that Antigravity worked fine while gemini-cli did not, but no local configuration change was reported to resolve the error.
No workaround that fixes the error is present in the thread. Since the issue is closed, the practical next step is general advice: check whether a newer gemini-cli version has been released and retry the request. If the error continues, open a new issue and include the client information shown by the CLI (version, git commit, model, OS, auth method).
Did this work for you?What a GitHub user tried on GitHub (Didn't work)
Made a normal request in gemini-cli 0.27.3 on Windows; every request failed with the 'candidates' error and the CLI looped retrying the same request.
Source: https://github.com/google-gemini/gemini-cli/issues/18621 (opens external site)
Did this work for you?What @scottbecker tried on GitHub (Didn't work)
Downgraded gemini-cli from 0.27.3 to 0.27.2 and tried again; the same error still occurred, leading the user to suspect a server-side update.
Did this work for you?What @heitorpolidoro tried on GitHub (Didn't work)
Disabled all extensions and MCPs, then tried again; the error still occurred.
Did this work for you?
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