diff --git a/CHANGELOG.md b/CHANGELOG.md
index e099972894..c56e2ec4a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,8 @@
 - Fix: 一部のページ内リンクが正しく動作しない問題を修正
 - Fix: 周年の実績が閏年を考慮しない問題を修正
 - Fix: ローカルURLのプレビューポップアップが左上に表示される
+- Fix: WebGL2をサポートしないブラウザで「季節に応じた画面の演出」が有効になっているとき、Misskeyが起動できなくなる問題を修正  
+  (Cherry-picked from https://activitypub.software/TransFem-org/Sharkey/-/merge_requests/459)
 
 ### Server
 - Enhance: エンドポイント`antennas/update`の必須項目を`antennaId`のみに
diff --git a/packages/frontend/src/boot/main-boot.ts b/packages/frontend/src/boot/main-boot.ts
index 8016e8b0e0..5cb19f388a 100644
--- a/packages/frontend/src/boot/main-boot.ts
+++ b/packages/frontend/src/boot/main-boot.ts
@@ -75,27 +75,31 @@ export async function mainBoot() {
 			mainRouter.push('/search');
 		},
 	};
-
-	if (defaultStore.state.enableSeasonalScreenEffect) {
-		const month = new Date().getMonth() + 1;
-		if (defaultStore.state.hemisphere === 'S') {
-			// ▼南半球
-			if (month === 7 || month === 8) {
-				const SnowfallEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
-				new SnowfallEffect({}).render();
+	try {
+		if (defaultStore.state.enableSeasonalScreenEffect) {
+			const month = new Date().getMonth() + 1;
+			if (defaultStore.state.hemisphere === 'S') {
+				// ▼南半球
+				if (month === 7 || month === 8) {
+					const SnowfallEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
+					new SnowfallEffect({}).render();
+				}
+			} else {
+				// ▼北半球
+				if (month === 12 || month === 1) {
+					const SnowfallEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
+					new SnowfallEffect({}).render();
+				} else if (month === 3 || month === 4) {
+					const SakuraEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
+					new SakuraEffect({
+						sakura: true,
+					}).render();
+				}
 			}
-		} else {
-			// ▼北半球
-			if (month === 12 || month === 1) {
-				const SnowfallEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
-				new SnowfallEffect({}).render();
-			} else if (month === 3 || month === 4) {
-				const SakuraEffect = (await import('@/scripts/snowfall-effect.js')).SnowfallEffect;
-				new SakuraEffect({
-					sakura: true,
-				}).render();
-			}
-		}
+		}	
+	} catch (error) {
+		// console.error(error);
+		console.error('Failed to initialise the seasonal screen effect canvas context:', error);
 	}
 
 	if ($i) {
diff --git a/packages/frontend/src/scripts/snowfall-effect.ts b/packages/frontend/src/scripts/snowfall-effect.ts
index 11fcaa0716..d88bdb6660 100644
--- a/packages/frontend/src/scripts/snowfall-effect.ts
+++ b/packages/frontend/src/scripts/snowfall-effect.ts
@@ -155,7 +155,9 @@ export class SnowfallEffect {
 		max: 0.125,
 		easing: 0.0005,
 	};
-
+	/**
+	 * @throws {Error} - Thrown when it fails to get WebGL context for the canvas 
+	 */
 	constructor(options: {
 		sakura?: boolean;
 	}) {
diff --git a/packages/frontend/src/stream.ts b/packages/frontend/src/stream.ts
index 0c5ee06197..0d5bd78b09 100644
--- a/packages/frontend/src/stream.ts
+++ b/packages/frontend/src/stream.ts
@@ -8,7 +8,12 @@ import { markRaw } from 'vue';
 import { $i } from '@/account.js';
 import { wsOrigin } from '@/config.js';
 
+// heart beat interval in ms
+const HEART_BEAT_INTERVAL = 1000 * 60;
+
 let stream: Misskey.Stream | null = null;
+let timeoutHeartBeat: ReturnType<typeof setTimeout> | null = null;
+let lastHeartbeatCall = 0;
 
 export function useStream(): Misskey.Stream {
 	if (stream) return stream;
@@ -17,7 +22,18 @@ export function useStream(): Misskey.Stream {
 		token: $i.token,
 	} : null));
 
-	window.setTimeout(heartbeat, 1000 * 60);
+	if (timeoutHeartBeat) window.clearTimeout(timeoutHeartBeat);
+	timeoutHeartBeat = window.setTimeout(heartbeat, HEART_BEAT_INTERVAL);
+
+	// send heartbeat right now when last send time is over HEART_BEAT_INTERVAL
+	document.addEventListener('visibilitychange', () => {
+		if (
+			!stream
+			|| document.visibilityState !== 'visible'
+			|| Date.now() - lastHeartbeatCall < HEART_BEAT_INTERVAL
+		) return;
+		heartbeat();
+	});
 
 	return stream;
 }
@@ -26,5 +42,7 @@ function heartbeat(): void {
 	if (stream != null && document.visibilityState === 'visible') {
 		stream.heartbeat();
 	}
-	window.setTimeout(heartbeat, 1000 * 60);
+	lastHeartbeatCall = Date.now();
+	if (timeoutHeartBeat) window.clearTimeout(timeoutHeartBeat);
+	timeoutHeartBeat = window.setTimeout(heartbeat, HEART_BEAT_INTERVAL);
 }