diff --git a/apps/dashboard/src/components/layouts/dashboard-error-screen.tsx b/apps/dashboard/src/components/layouts/dashboard-error-screen.tsx
new file mode 100644
index 0000000..fce7310
--- /dev/null
+++ b/apps/dashboard/src/components/layouts/dashboard-error-screen.tsx
@@ -0,0 +1,182 @@
+import {
+	AlertCircleIcon,
+	LockIcon,
+	RefreshCwIcon,
+	SearchIcon,
+	WifiOffIcon,
+} from "@diffkit/icons";
+import { Button } from "@diffkit/ui/components/button";
+import { cn } from "@diffkit/ui/lib/utils";
+import { type ErrorComponentProps, useRouter } from "@tanstack/react-router";
+import type { ComponentType } from "react";
+import { useShowOrgSetupQueryState } from "#/lib/github-access-dialog-query";
+import { openGitHubAccessPrompt } from "#/lib/github-access-modal-store";
+
+type ErrorInfo = {
+	icon: ComponentType<{ size?: number; strokeWidth?: number }>;
+	iconClassName: string;
+	title: string;
+	description: string;
+	action: "retry" | "configure-access";
+};
+
+function getErrorInfo(error: Error): ErrorInfo {
+	const msg = error.message;
+	const lower = msg.toLowerCase();
+
+	if (lower.includes("rate limit") || lower.includes("429")) {
+		return {
+			icon: AlertCircleIcon,
+			iconClassName: "bg-amber-500/10 text-amber-500",
+			title: "Rate limit reached",
+			description:
+				"You've made too many requests. Wait a moment and try again.",
+			action: "retry",
+		};
+	}
+
+	if (
+		lower.includes("403") ||
+		lower.includes("forbidden") ||
+		lower.includes("not accessible by integration") ||
+		lower.includes("insufficient permissions")
+	) {
+		return {
+			icon: LockIcon,
+			iconClassName: "bg-amber-500/10 text-amber-500",
+			title: "Access not configured",
+			description:
+				"DiffKit doesn't have access to this resource. Add the repository or organization in your GitHub app settings.",
+			action: "configure-access",
+		};
+	}
+
+	if (lower.includes("404") || lower.includes("not found")) {
+		return {
+			icon: SearchIcon,
+			iconClassName: "bg-muted-foreground/10 text-muted-foreground",
+			title: "Not found",
+			description:
+				"This resource doesn't exist or you don't have access to it.",
+			action: "retry",
+		};
+	}
+
+	if (
+		lower.includes("network") ||
+		lower.includes("fetch failed") ||
+		lower.includes("econnrefused") ||
+		lower.includes("enotfound") ||
+		lower.includes("failed to fetch")
+	) {
+		return {
+			icon: WifiOffIcon,
+			iconClassName: "bg-amber-500/10 text-amber-500",
+			title: "Connection failed",
+			description:
+				"Could not reach the server. Check your internet connection and try again.",
+			action: "retry",
+		};
+	}
+
+	if (lower.includes("timeout") || lower.includes("timed out")) {
+		return {
+			icon: AlertCircleIcon,
+			iconClassName: "bg-amber-500/10 text-amber-500",
+			title: "Request timed out",
+			description:
+				"The request took too long to complete. Try again in a moment.",
+			action: "retry",
+		};
+	}
+
+	return {
+		icon: AlertCircleIcon,
+		iconClassName: "bg-destructive/10 text-destructive",
+		title: "Something went wrong",
+		description:
+			msg ||
+			"An unexpected error occurred. Please try again or refresh the page.",
+		action: "retry",
+	};
+}
+
+/** Strip the trailing ` - GET https://…` suffix that octokit appends. */
+function cleanErrorMessage(msg: string): string | null {
+	if (!msg) return null;
+	const cleaned = msg
+		.replace(/\s*-\s+(GET|POST|PUT|PATCH|DELETE|HEAD)\s+https?:\/\/\S+$/i, "")
+		.trim();
+	return cleaned || null;
+}
+
+export function DashboardErrorScreen({ error, reset }: ErrorComponentProps) {
+	const router = useRouter();
+	const {
+		icon: Icon,
+		iconClassName,
+		title,
+		description,
+		action,
+	} = getErrorInfo(error);
+	const detail = cleanErrorMessage(error.message);
+
+	return (
+		<div className="flex h-full items-center justify-center px-6 py-16">
+			<div className="mx-auto flex w-full max-w-md flex-col items-center gap-6 text-center">
+				<div
+					className={cn(
+						"flex size-12 items-center justify-center rounded-xl",
+						iconClassName,
+					)}
+				>
+					<Icon size={24} strokeWidth={1.75} />
+				</div>
+
+				<div className="flex flex-col gap-1.5">
+					<h1 className="text-lg font-semibold tracking-tight">{title}</h1>
+					<p className="text-sm text-muted-foreground text-balance">
+						{description}
+					</p>
+				</div>
+
+				{detail && (
+					<p className="max-w-sm rounded-lg bg-surface-1 px-3 py-2 font-mono text-xs text-muted-foreground">
+						{detail}
+					</p>
+				)}
+
+				<div className="flex items-center gap-2">
+					{action === "configure-access" ? <ConfigureAccessButton /> : null}
+					<Button
+						variant="outline"
+						size="sm"
+						iconLeft={<RefreshCwIcon />}
+						onClick={() => {
+							reset();
+							router.invalidate();
+						}}
+					>
+						Try again
+					</Button>
+				</div>
+			</div>
+		</div>
+	);
+}
+
+function ConfigureAccessButton() {
+	const [, setShowOrgSetup] = useShowOrgSetupQueryState();
+
+	return (
+		<Button
+			size="sm"
+			onClick={() => {
+				openGitHubAccessPrompt({ source: "warning" });
+				void setShowOrgSetup(true);
+			}}
+		>
+			Configure access
+		</Button>
+	);
+}
diff --git a/apps/dashboard/src/components/layouts/error-screen.tsx b/apps/dashboard/src/components/layouts/error-screen.tsx
index 7dab3e6..324a509 100644
--- a/apps/dashboard/src/components/layouts/error-screen.tsx
+++ b/apps/dashboard/src/components/layouts/error-screen.tsx
@@ -1,40 +1,10 @@
-import { AlertCircleIcon, RefreshCwIcon } from "@diffkit/icons";
-import { Button } from "@diffkit/ui/components/button";
-import { type ErrorComponentProps, useRouter } from "@tanstack/react-router";
-
-export function ErrorScreen({ reset }: ErrorComponentProps) {
-	const router = useRouter();
+import type { ErrorComponentProps } from "@tanstack/react-router";
+import { DashboardErrorScreen } from "./dashboard-error-screen";
 
+export function ErrorScreen(props: ErrorComponentProps) {
 	return (
-		<div className="flex min-h-dvh items-center justify-center px-6 py-16">
-			<div className="mx-auto flex w-full max-w-md flex-col items-center gap-6 text-center">
-				<div className="flex size-12 items-center justify-center rounded-xl bg-destructive/10 text-destructive">
-					<AlertCircleIcon size={24} strokeWidth={1.75} />
-				</div>
-
-				<div className="flex flex-col gap-1.5">
-					<h1 className="text-lg font-semibold tracking-tight">
-						Something went wrong
-					</h1>
-					<p className="text-sm text-muted-foreground text-balance">
-						An unexpected error occurred. Please try again or refresh the page.
-					</p>
-				</div>
-
-				<div className="flex items-center gap-2">
-					<Button
-						variant="outline"
-						size="sm"
-						iconLeft={<RefreshCwIcon />}
-						onClick={() => {
-							reset();
-							router.invalidate();
-						}}
-					>
-						Try again
-					</Button>
-				</div>
-			</div>
+		<div className="min-h-dvh">
+			<DashboardErrorScreen {...props} />
 		</div>
 	);
 }
diff --git a/apps/dashboard/src/components/pulls/detail/pull-detail-activity.tsx b/apps/dashboard/src/components/pulls/detail/pull-detail-activity.tsx
index f5ce918..03927a1 100644
--- a/apps/dashboard/src/components/pulls/detail/pull-detail-activity.tsx
+++ b/apps/dashboard/src/components/pulls/detail/pull-detail-activity.tsx
@@ -523,7 +523,7 @@ function ReviewsSection({
 														repo,
 														pullNumber,
 														reviewId: review.id,
-														message: "Dismissed via QuickHub",
+														message: "Dismissed via DiffKit",
 													},
 												})
 													.then((result) => {
diff --git a/apps/dashboard/src/lib/github.server.test.ts b/apps/dashboard/src/lib/github.server.test.ts
index 3739bab..283936b 100644
--- a/apps/dashboard/src/lib/github.server.test.ts
+++ b/apps/dashboard/src/lib/github.server.test.ts
@@ -93,7 +93,7 @@ describe("getGitHubClient", () => {
 		};
 
 		expect(options.auth).toBe("github-token");
-		expect(options.userAgent).toBe("quickhub-dashboard");
+		expect(options.userAgent).toBe("diffkit-dashboard");
 		expect(options.retry).toEqual({ enabled: true });
 		expect(options.throttle.enabled).toBe(true);
 		expect(options.throttle.id).toBe("github-user:user-123");
diff --git a/apps/dashboard/src/lib/github.server.ts b/apps/dashboard/src/lib/github.server.ts
index c1024bb..b86a9bf 100644
--- a/apps/dashboard/src/lib/github.server.ts
+++ b/apps/dashboard/src/lib/github.server.ts
@@ -7,7 +7,7 @@ import {
 } from "./github-app.server";
 import { configureGitHubRequestPolicies } from "./github-request-policy";
 
-const GITHUB_CLIENT_USER_AGENT = "quickhub-dashboard";
+const GITHUB_CLIENT_USER_AGENT = "diffkit-dashboard";
 const GITHUB_SECONDARY_RATE_LIMIT_FALLBACK_SECONDS = 60;
 
 type GitHubThrottleRequestOptions = {
diff --git a/apps/dashboard/src/router.tsx b/apps/dashboard/src/router.tsx
index 6e50999..fe1c77d 100644
--- a/apps/dashboard/src/router.tsx
+++ b/apps/dashboard/src/router.tsx
@@ -1,5 +1,6 @@
 import { createRouter as createTanStackRouter } from "@tanstack/react-router";
 import { setupRouterSsrQueryIntegration } from "@tanstack/react-router-ssr-query";
+import { DashboardErrorScreen } from "#/components/layouts/dashboard-error-screen";
 import {
 	AppQueryClientProvider,
 	createAppQueryClient,
@@ -17,6 +18,7 @@ export function getRouter() {
 		defaultPreload: "intent",
 		defaultPreloadStaleTime: 0,
 		defaultPendingMs: 0,
+		defaultErrorComponent: DashboardErrorScreen,
 		Wrap: ({ children }) => (
 			<AppQueryClientProvider queryClient={queryClient}>
 				{children}
diff --git a/packages/icons/src/index.ts b/packages/icons/src/index.ts
index 3a380e1..57622ba 100644
--- a/packages/icons/src/index.ts
+++ b/packages/icons/src/index.ts
@@ -44,6 +44,7 @@ export {
   Link02Icon as ExternalLinkIcon,
   Loading03Icon as LoaderCircleIcon,
   Location01Icon as LocationIcon,
+  LockIcon,
   Mail01Icon as MailIcon,
   Message01Icon as MessageIcon,
   Moon02Icon as MoonIcon,
@@ -64,6 +65,7 @@ export {
   UserCircleIcon,
   UserGroupIcon as FollowersIcon,
   ViewIcon,
+  WifiDisconnected01Icon as WifiOffIcon,
 } from "@hugeicons/react";
 export { GitHubLogo, GitHubWordmarkLogo } from "./brand-logos";
 export { PenIcon } from "./pen-icon";