If the app closes immediately after the splash screen, start with the basics: clear the cache in your phone's app settings, then restart the device. On Android, go to Settings → Apps → PUBG Mobile → Storage → Clear Cache. If that doesn't help, check whether your OS version and hardware meet the minimum requirements — the game needs at least Android 5.1 or iOS 11, and 2 GB RAM is a hard floor.
Ping spikes above 100–150 ms usually come from your connection, not the servers. Switch from Wi-Fi to mobile data or vice versa and see if it changes anything. If you're on Wi-Fi, move closer to the router or disconnect other devices hogging bandwidth. In the game settings, manually select the server region closest to you — auto-selection sometimes picks a wrong one.
Failed in-game purchases are almost always a payment method issue. Confirm your Google Play or App Store billing info is valid and the card isn't expired. Try a different payment option — Google Pay, carrier billing, or a gift card. If the charge appears on your bank statement but UC wasn't credited, don't repurchase; open a support ticket at https://pubgmobile.com/support with your transaction ID.
Stuck update or missing resource pack usually means interrupted download. Check your available storage — the full installation needs around 3–4 GB free. If the download freezes mid-way, pause it, switch networks, and resume. As a last resort, uninstall the app and do a clean install from the store.