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  • AgentArmorHQ teamTeam3d agoNeeds helpSolved

    Cline VS Code error "API Streaming failed: MCP hub not available" — how to fix?

    After installing or updating the Cline extension in VS Code on Windows 11 with a WSL project open, sending a message in the Cline chat fails with "API Streaming failed: MCP hub not available". The error appears on fresh installs and after updates, using different providers and models (Claude 3.5 Sonnet, Gemini, DeepSeek). What fixes or workarounds are known?

    Originally asked on GitHub: https://github.com/cline/cline/issues/969

    6 answers

    • Best answerAgentArmorHQ teamTeam3d ago

      No official fix or root cause was posted; the issue was closed as completed without a maintainer explanation. The workaround that helped several users was a full restart of VS Code.

      • Fully quit VS Code and start it again. A contributor suggested this after a user on Windsurf with Cline saw the error following an update, and another commenter confirmed that a restart resolved it.
      • Moving the Cline panel to the panel or secondary sidebar position was suggested as a way to reset the view without a full restart. One user said that worked, but another reported the error came back after moving it.
      • For a related problem where Ollama returned 404, one user reverted Cline to v3.2 and said everything worked. Another user later tried v3.2 while still getting the MCP Hub error and the error persisted.

      One commenter also ran into a different error after restarting — "Cannot read properties of undefined (reading 'type')" with DeepSeek reasoner — so the failure is not necessarily identical across setups. The thread does not say whether this is related to specific providers, models, or the WSL project workspace.

      General advice based only on the thread: if you hit this after an update or fresh install, try a full quit-and-restart of VS Code before changing extension versions or API provider settings.

      Did this work for you?
    • AgentArmorHQ teamTeam3d ago

      What @skyfallwastaken tried on GitHub (Worked)

      After a contributor suggested restarting VS Code, this user confirmed a full restart resolved the "MCP hub not available" error.

      Source: https://github.com/cline/cline/issues/969#issuecomment-2558396970 (opens external site)

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    • AgentArmorHQ teamTeam3d ago

      What @agileandy tried on GitHub (Worked)

      Reverted Cline to v3.2 while Ollama was returning 404 and reported that everything worked afterwards.

      Source: https://github.com/cline/cline/issues/969#issuecomment-2615413942 (opens external site)

      Did this work for you?
    • AgentArmorHQ teamTeam3d ago

      What @tpdph tried on GitHub (Worked)

      Moved the Cline panel to the panel or secondary sidebar position and said it seemed to reset without needing a full restart.

      Source: https://github.com/cline/cline/issues/969#issuecomment-2561363919 (opens external site)

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    • AgentArmorHQ teamTeam3d ago

      What @liucclear tried on GitHub (Didn't work)

      Moved the Cline panel to the panel or secondary sidebar position, but the error returned.

      Source: https://github.com/cline/cline/issues/969#issuecomment-2566594165 (opens external site)

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    • AgentArmorHQ teamTeam3d ago

      What @chisgit tried on GitHub (Didn't work)

      Installed Cline v3.2 while still getting the MCP Hub error, and the error persisted.

      Source: https://github.com/cline/cline/issues/969#issuecomment-2653033041 (opens external site)

      Did this work for you?

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