{"record":{"id":"b267e0400adc0972","repo":"zellij-org/zellij","slug":"failed-to-find-active-pane-id-for-client-client-i","errorCode":null,"errorMessage":"failed to find active pane id for client {client_id}","messagePattern":"failed to find active pane id for client (.+?)","errorType":"exception","errorClass":"anyhow::Error","httpStatus":null,"severity":"error","filePath":"zellij-server/src/tab/mod.rs","lineNumber":4359,"sourceCode":"        raw_input_bytes_are_kitty: bool,\n        client_id: ClientId,\n    ) -> Result<bool> {\n        // returns true if a UI update should be triggered (eg. if a command pane\n        // was closed with ctrl-c)\n        let err_context = || {\n            format!(\n                \"failed to write to active terminal for client {client_id} - msg: {raw_input_bytes:?}\"\n            )\n        };\n\n        self.clear_search(client_id);\n        self.mouse_help_text_visible.clear();\n        let pane_id = if self.floating_panes.panes_are_visible() {\n            self.floating_panes\n                .get_active_pane_id(client_id)\n                .or_else(|| self.tiled_panes.get_active_pane_id(client_id))\n                .ok_or_else(|| {\n                    anyhow!(format!(\n                        \"failed to find active pane id for client {client_id}\"\n                    ))\n                })\n                .with_context(err_context)?\n        } else {\n            self.tiled_panes\n                .get_active_pane_id(client_id)\n                .with_context(err_context)?\n        };\n        // Can't use 'err_context' here since it borrows 'raw_input_bytes'\n        self.write_to_pane_id(\n            key_with_modifier,\n            raw_input_bytes,\n            raw_input_bytes_are_kitty,\n            pane_id,\n            Some(client_id),\n            None,\n        )","sourceCodeStart":4341,"sourceCodeEnd":4377,"githubUrl":"https://github.com/zellij-org/zellij/blob/474ea0cef620c83d6ec05a7c28c7f80c4f63bbbb/zellij-server/src/tab/mod.rs#L4341-L4377","documentation":"Thrown by Tab::write_to_active_terminal in zellij-server when routing a keystroke: with floating panes visible it asks FloatingPanes for the client's active pane, falls back to TiledPanes, and errors only when BOTH return None. It means keyboard input arrived for a client that has no active pane registered in either the floating or the tiled pane set of this tab. The accompanying context names the raw input bytes that could not be delivered.","triggerScenarios":"A key event for client X reaches write_to_active_terminal after the last pane of the tab exited, before the client's focus was initialized on connect, or while focus sits on a pane that is recorded in neither self.floating_panes nor self.tiled_panes. Note this path is more forgiving than Tab::get_active_pane_id (tab/mod.rs:3732) because it adds the tiled fallback when floating panes are visible, so hitting it requires no active pane in either map.","commonSituations":"Race between the final pane/command pane closing (e.g. Ctrl-c in a command-pane tab) and in-flight keystrokes; a reconnecting or web client sending input before the first render assigned focus; focus state corrupted by rapid tab switching or pane moves.","solutions":["Reproduce with one client and check whether the tab still shows any pane at the moment of the keystroke; if the tab is empty, the error is expected noise from late input — switch or close the tab instead of typing.","If panes are visible, capture which key sequence triggers it (the err_context prints raw_input_bytes) and check whether it happens right after a pane closes — that points to a focus-reassignment race worth reporting upstream.","Update zellij; active-pane bookkeeping around closing panes and reconnecting clients is actively fixed between releases.","If you embed zellij-server, ensure set_active_pane/focus is called for every client on connect and after the last pane of a tab exits before forwarding input."],"exampleFix":null,"handlingStrategy":"validation","validationCode":"// before forwarding input for a client, ensure focus exists\nif tab.get_active_pane_id(client_id).is_none() {\n    // no destination: initialize focus or drop the input instead of erroring\n    if let Some(first) = tab.get_active_pane_id_or_first_selectable(client_id) {\n        tab.focus_pane(first, client_id);\n    } else {\n        return Ok(()); // tab has no panes; nothing to write to\n    }\n}","typeGuard":null,"tryCatchPattern":"// treat a missing active pane as a no-op race, not a fatal error\nmatch tab.write_to_active_terminal(key, bytes, kitty, client_id, None) {\n    Ok(_) => {},\n    Err(e) if e.to_string().contains(\"failed to find active pane id\") => {\n        log::debug!(\"input dropped: no active pane for client {client_id}\");\n    },\n    Err(e) => return Err(e),\n}","preventionTips":["Assign focus to every client on connect and re-assign it (first selectable pane) whenever a tab's last pane closes.","Never queue input for a tab whose panes have all exited; check pane liveness before dispatch.","In embedder code, prefer get_active_pane_id_or_first_selectable over raw get_active_pane_id when a fallback focus is acceptable."],"tags":["zellij","rust","active-pane","input-handling","race-condition"],"backgroundTag":"missing-active-pane","analyzedSha":"474ea0cef620c83d6ec05a7c28c7f80c4f63bbbb","analyzedAt":"2026-08-19T07:42:58.758Z","contentChangedAt":"2026-08-19T07:42:58.758Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}