diff --git a/src/daemon/launchd.test.ts b/src/daemon/launchd.test.ts
index 341f071de91..f101a17a687 100644
--- a/src/daemon/launchd.test.ts
+++ b/src/daemon/launchd.test.ts
@@ -18,6 +18,8 @@ const state = vi.hoisted(() => ({
   listOutput: "",
   printOutput: "",
   bootstrapError: "",
+  bootstrapFailuresRemaining: Infinity,
+  loadError: "",
   kickstartError: "",
   kickstartFailuresRemaining: 0,
   dirs: new Set<string>(),
@@ -74,9 +76,13 @@ vi.mock("./exec-file.js", () => ({
     if (call[0] === "print") {
       return { stdout: state.printOutput, stderr: "", code: 0 };
     }
-    if (call[0] === "bootstrap" && state.bootstrapError) {
+    if (call[0] === "bootstrap" && state.bootstrapError && state.bootstrapFailuresRemaining > 0) {
+      state.bootstrapFailuresRemaining -= 1;
       return { stdout: "", stderr: state.bootstrapError, code: 1 };
     }
+    if (call[0] === "load" && state.loadError) {
+      return { stdout: "", stderr: state.loadError, code: 1 };
+    }
     if (call[0] === "kickstart" && state.kickstartError && state.kickstartFailuresRemaining > 0) {
       state.kickstartFailuresRemaining -= 1;
       return { stdout: "", stderr: state.kickstartError, code: 1 };
@@ -152,6 +158,8 @@ beforeEach(() => {
   state.listOutput = "";
   state.printOutput = "";
   state.bootstrapError = "";
+  state.bootstrapFailuresRemaining = Infinity;
+  state.loadError = "";
   state.kickstartError = "";
   state.kickstartFailuresRemaining = 0;
   state.dirs.clear();
@@ -438,6 +446,7 @@ describe("launchd install", () => {
 
   it("shows actionable guidance when launchctl gui domain does not support bootstrap", async () => {
     state.bootstrapError = "Bootstrap failed: 125: Domain does not support specified action";
+    state.loadError = "Could not find domain for user gui: 1000";
     const env = createDefaultLaunchdEnv();
     let message = "";
     try {
@@ -452,6 +461,53 @@ describe("launchd install", () => {
     expect(message).toContain("logged-in macOS GUI session");
     expect(message).toContain("wrong user (including sudo)");
     expect(message).toContain("https://docs.openclaw.ai/gateway");
+    // Verify that `load -w` was attempted as a fallback before giving up.
+    expect(state.launchctlCalls.some((c) => c[0] === "load")).toBe(true);
+  });
+
+  it("falls back to launchctl load when gui domain is unavailable", async () => {
+    state.bootstrapError = "Bootstrap failed: 125: Domain does not support specified action";
+    // loadError is empty → launchctl load succeeds
+    const env = createDefaultLaunchdEnv();
+    const stdout = new PassThrough();
+    await installLaunchAgent({
+      env,
+      stdout,
+      programArguments: defaultProgramArguments,
+    });
+    expect(state.launchctlCalls.some((c) => c[0] === "load" && c[1] === "-w")).toBe(true);
+  });
+
+  it("retries bootstrap after bootout when service is already registered", async () => {
+    state.bootstrapError = "Bootstrap failed: 5: Input/output error";
+    state.bootstrapFailuresRemaining = 1; // first bootstrap fails, retry succeeds
+    const env = createDefaultLaunchdEnv();
+    const stdout = new PassThrough();
+    await installLaunchAgent({
+      env,
+      stdout,
+      programArguments: defaultProgramArguments,
+    });
+    // Verify bootout was called between the two bootstrap attempts.
+    const bootoutAfterBootstrap = state.launchctlCalls.findIndex(
+      (c, i) =>
+        c[0] === "bootout" &&
+        i > state.launchctlCalls.findIndex((b) => b[0] === "bootstrap"),
+    );
+    expect(bootoutAfterBootstrap).toBeGreaterThanOrEqual(0);
+  });
+
+  it("falls back to launchctl load for 'Could not find domain' error from issue #8619", async () => {
+    state.bootstrapError = "Could not find domain for user gui: 1000";
+    // loadError is empty → launchctl load succeeds
+    const env = createDefaultLaunchdEnv();
+    const stdout = new PassThrough();
+    await installLaunchAgent({
+      env,
+      stdout,
+      programArguments: defaultProgramArguments,
+    });
+    expect(state.launchctlCalls.some((c) => c[0] === "load" && c[1] === "-w")).toBe(true);
   });
 
   it("surfaces generic bootstrap failures without GUI-specific guidance", async () => {
diff --git a/src/daemon/launchd.ts b/src/daemon/launchd.ts
index 13d6fd46d33..ad4a70530e7 100644
--- a/src/daemon/launchd.ts
+++ b/src/daemon/launchd.ts
@@ -201,12 +201,47 @@ async function bootstrapLaunchAgentOrThrow(params: {
     return;
   }
   const detail = (boot.stderr || boot.stdout).trim();
-  if (isUnsupportedGuiDomain(detail)) {
-    throwBootstrapGuiSessionError({
-      detail,
-      domain: params.domain,
-      actionHint: params.actionHint,
-    });
+  // Track the most relevant error detail across retries so that the final
+  // error message shown to the user reflects the actual failure, not a stale
+  // "already bootstrapped" message from an earlier attempt.
+  let effectiveDetail = detail;
+
+  // If the service is already registered (e.g. re-install without prior uninstall),
+  // bootout the stale registration and retry once.
+  if (isAlreadyBootstrapped(detail)) {
+    await execLaunchctl(["bootout", params.domain, params.plistPath]);
+    const retry = await execLaunchctl(["bootstrap", params.domain, params.plistPath]);
+    if (retry.code === 0) {
+      return;
+    }
+    const retryDetail = (retry.stderr || retry.stdout).trim();
+    effectiveDetail = retryDetail;
+    if (isUnsupportedGuiDomain(retryDetail)) {
+      // Fall through to the legacy load fallback below.
+    } else if (!isAlreadyBootstrapped(retryDetail)) {
+      throw new Error(`launchctl bootstrap failed: ${retryDetail}`);
+    }
+  }
+
+  // If the gui/ domain is unavailable (SSH, headless, or sudo), try the
+  // deprecated-but-universal `launchctl load` as a last resort before giving up.
+  if (isUnsupportedGuiDomain(effectiveDetail) || isAlreadyBootstrapped(effectiveDetail)) {
+    const load = await execLaunchctl(["load", "-w", params.plistPath]);
+    if (load.code === 0) {
+      return;
+    }
+    const loadDetail = (load.stderr || load.stdout).trim();
+    // Only show GUI-session guidance when the failure is actually gui-domain related
+    // and the load fallback didn't reveal a different, more actionable error.
+    if (isUnsupportedGuiDomain(effectiveDetail)) {
+      const isLoadDifferentError = loadDetail && !isUnsupportedGuiDomain(loadDetail);
+      throwBootstrapGuiSessionError({
+        detail: isLoadDifferentError ? `${loadDetail} (bootstrap: ${effectiveDetail})` : effectiveDetail,
+        domain: params.domain,
+        actionHint: params.actionHint,
+      });
+    }
+    throw new Error(`launchctl load failed: ${loadDetail || effectiveDetail}`);
   }
   throw new Error(`launchctl bootstrap failed: ${detail}`);
 }
@@ -444,7 +479,21 @@ function isUnsupportedGuiDomain(detail: string): boolean {
   const normalized = detail.toLowerCase();
   return (
     normalized.includes("domain does not support specified action") ||
-    normalized.includes("bootstrap failed: 125")
+    normalized.includes("bootstrap failed: 125") ||
+    normalized.includes("could not find domain for")
+  );
+}
+
+function isAlreadyBootstrapped(detail: string): boolean {
+  const normalized = detail.toLowerCase();
+  // Match explicit "already loaded" / "already bootstrapped" messages.
+  // We intentionally do NOT match the generic "bootstrap failed: 5"
+  // (Input/output error) because that code also fires for malformed or
+  // unreadable plists, and treating those as "already loaded" would mask
+  // real bootstrap failures.
+  return (
+    normalized.includes("already loaded") ||
+    normalized.includes("already bootstrapped")
   );
 }