It is strongly recommended to check the new allocated pointer is not null

FAQ-#3.md

@@ -39,12 +39,17 @@ void setup() {
 ...
 }
 
-void PixelCountChanged(uint16_t newCount) {
+bool PixelCountChanged(uint16_t newCount) {
     if (strip != NULL) {  
        delete strip; // delete the previous dynamically created strip
     }
     strip = new NeoPixelBus<NeoGrbFeature, Neo800KbpsMethod>(newCount, Pin); // and recreate with new count
+    if (strip == NULL) {
+        Serial.println("OUT OF MEMORY");
+        return false;
+    }
     strip->Begin();
+    return true;
 }
 
 void loop() {