diff --git a/.changeset/short-days-itch.md b/.changeset/short-days-itch.md
new file mode 100644
index 000000000..39d9f920e
--- /dev/null
+++ b/.changeset/short-days-itch.md
@@ -0,0 +1,5 @@
+---
+"@solidjs/start": patch
+---
+
+fix #1645 flash encoding, and improve error handling
diff --git a/examples/with-auth/src/lib/index.ts b/examples/with-auth/src/lib/index.ts
index 71f31f3ee..5193db938 100644
--- a/examples/with-auth/src/lib/index.ts
+++ b/examples/with-auth/src/lib/index.ts
@@ -20,7 +20,7 @@ export const getUser = query(async () => {
     return { id: user.id, username: user.username };
   } catch {
     await logoutSession();
-    redirect("/login");
+    throw redirect("/login");
   }
 }, "user");
 
diff --git a/packages/start/src/runtime/server-handler.ts b/packages/start/src/runtime/server-handler.ts
index 7dbd5c165..255283168 100644
--- a/packages/start/src/runtime/server-handler.ts
+++ b/packages/start/src/runtime/server-handler.ts
@@ -252,13 +252,13 @@ function handleNoJS(result: any, request: Request, parsed: any[], thrown?: boole
   if (result) {
     headers.append(
       "Set-Cookie",
-      `flash=${JSON.stringify({
-        url: url.pathname + encodeURIComponent(url.search),
+      `flash=${encodeURIComponent(JSON.stringify({
+        url: url.pathname + url.search,
         result: isError ? result.message : result,
         thrown: thrown,
         error: isError,
         input: [...parsed.slice(0, -1), [...parsed[parsed.length - 1].entries()]]
-      })}; Secure; HttpOnly;`
+      }))}; Secure; HttpOnly;`
     );
   }
   return new Response(null, {
diff --git a/packages/start/src/server/pageEvent.ts b/packages/start/src/server/pageEvent.ts
index 4cb11d66d..c105673b0 100644
--- a/packages/start/src/server/pageEvent.ts
+++ b/packages/start/src/server/pageEvent.ts
@@ -1,25 +1,27 @@
-import {
-  getCookie,
-  setCookie
-} from "vinxi/http";
+import { getCookie, setCookie } from "vinxi/http";
 import { createRoutes } from "../router/FileRoutes";
 import { FetchEvent, PageEvent } from "./types";
 
 function initFromFlash(ctx: FetchEvent) {
   const flash = getCookie(ctx.nativeEvent, "flash");
   if (!flash) return;
-  let param = JSON.parse(flash);
-  if (!param || !param.result) return;
-  const input = [...param.input.slice(0, -1), new Map(param.input[param.input.length - 1])];
-  setCookie(ctx.nativeEvent, "flash", "", { maxAge: 0 });
-  const result = param.error ? new Error(param.result) : param.result;
-  return {
-    input,
-    url: param.url,
-    pending: false,
-    result: param.thrown ? undefined : result,
-    error: param.thrown ? result : undefined,
-  };
+  try {
+    let param = JSON.parse(flash);
+    if (!param || !param.result) return;
+    const input = [...param.input.slice(0, -1), new Map(param.input[param.input.length - 1])];
+    const result = param.error ? new Error(param.result) : param.result;
+    return {
+      input,
+      url: param.url,
+      pending: false,
+      result: param.thrown ? undefined : result,
+      error: param.thrown ? result : undefined
+    };
+  } catch (e) {
+    console.error(e);
+  } finally {
+    setCookie(ctx.nativeEvent, "flash", "", { maxAge: 0 });
+  }
 }
 
 export async function createPageEvent(ctx: FetchEvent) {
@@ -32,7 +34,9 @@ export async function createPageEvent(ctx: FetchEvent) {
     manifest: await clientManifest.json(),
     assets: [
       ...(await clientManifest.inputs[clientManifest.handler]!.assets()),
-      ...(import.meta.env.DEV ? await clientManifest.inputs[import.meta.env.START_APP]!.assets(): []),
+      ...(import.meta.env.DEV
+        ? await clientManifest.inputs[import.meta.env.START_APP]!.assets()
+        : []),
       ...(import.meta.env.START_ISLANDS
         ? (await serverManifest.inputs[serverManifest.handler]!.assets()).filter(
             s => (s as any).attrs.rel !== "modulepreload"