diff --git a/core/ui/src/main/java/com/sadellie/unitto/core/ui/UIUtils.kt b/core/ui/src/main/java/com/sadellie/unitto/core/ui/UIUtils.kt
index 42b4a605..b055c7af 100644
--- a/core/ui/src/main/java/com/sadellie/unitto/core/ui/UIUtils.kt
+++ b/core/ui/src/main/java/com/sadellie/unitto/core/ui/UIUtils.kt
@@ -18,13 +18,20 @@
 
 package com.sadellie.unitto.core.ui
 
+import android.content.ActivityNotFoundException
 import android.content.Context
 import android.content.Intent
 import android.net.Uri
+import android.widget.Toast
+import com.sadellie.unitto.core.base.R
 
 /**
  * Open given link in browser
  */
 fun openLink(mContext: Context, url: String) {
-    mContext.startActivity(Intent(Intent.ACTION_VIEW).setData(Uri.parse(url)))
+    try {
+        mContext.startActivity(Intent(Intent.ACTION_VIEW).setData(Uri.parse(url)))
+    } catch (e: ActivityNotFoundException) {
+        Toast.makeText(mContext, R.string.error_label, Toast.LENGTH_SHORT).show()
+    }
 }
diff --git a/feature/datecalculator/src/main/java/com/sadellie/unitto/feature/datecalculator/addsubtract/AddSubtractPage.kt b/feature/datecalculator/src/main/java/com/sadellie/unitto/feature/datecalculator/addsubtract/AddSubtractPage.kt
index a852b2ce..e7e2279d 100644
--- a/feature/datecalculator/src/main/java/com/sadellie/unitto/feature/datecalculator/addsubtract/AddSubtractPage.kt
+++ b/feature/datecalculator/src/main/java/com/sadellie/unitto/feature/datecalculator/addsubtract/AddSubtractPage.kt
@@ -19,9 +19,11 @@
 package com.sadellie.unitto.feature.datecalculator.addsubtract
 
 import android.annotation.SuppressLint
+import android.content.ActivityNotFoundException
 import android.content.Context
 import android.content.Intent
 import android.provider.CalendarContract
+import android.widget.Toast
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.ExperimentalLayoutApi
@@ -220,7 +222,11 @@ private fun Context.addEvent(start: ZonedDateTime, end: ZonedDateTime) {
         .putExtra(CalendarContract.EXTRA_EVENT_END_TIME, endMillis)
         .putExtra(CalendarContract.Events.AVAILABILITY, CalendarContract.Events.AVAILABILITY_BUSY)
 
-    startActivity(intent)
+    try {
+        startActivity(intent)
+    } catch (e: ActivityNotFoundException) {
+        Toast.makeText(this, R.string.error_label, Toast.LENGTH_SHORT).show()
+    }
 }
 
 @Preview