diff --git a/src/hooks/useCourseData.tsx b/src/hooks/useCourseData.tsx
index 737bc80..6db514f 100644
--- a/src/hooks/useCourseData.tsx
+++ b/src/hooks/useCourseData.tsx
@@ -101,7 +101,7 @@ export function useCourseData(courses: any[]) {
       setIsPending(false);
     } catch (error) {
       localStorage.removeItem('lastRequestTime');
-      // setIsError(true);
+      setIsError(true);
       setIsPending(false);
     }
   }, [courses]);
diff --git a/src/lib/utils.ts b/src/lib/utils.ts
index d6b1e52..e73cc7d 100644
--- a/src/lib/utils.ts
+++ b/src/lib/utils.ts
@@ -6,9 +6,17 @@ export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs));
 }
 
-export function isCurrentDateInRange(dateRange: string) {
+export function isCurrentDateInRange(dateRange: string | null) {
+  if (!dateRange || !dateRange.includes(' ~ ')) {
+    return false;
+  }
+
   const [startStr, endStr] = dateRange.split(' ~ ');
 
+  if (!startStr || !endStr) {
+    return false;
+  }
+
   const startDate = new Date(startStr.replace(/-/g, '/'));
   const endDate = new Date(endStr.replace(/-/g, '/'));
 
@@ -16,7 +24,9 @@ export function isCurrentDateInRange(dateRange: string) {
 
   return currentDate >= startDate && currentDate <= endDate;
 }
-export function isCurrentDateByDate(date: string) {
+
+export function isCurrentDateByDate(date: string | null) {
+  if (!date || date.length <= 1) return false;
   const endDate = new Date(date);
   const currentDate = new Date();
   return currentDate <= endDate;