Before doing anything, you have to make sure you are on the latest version of the game. you can do that by following below:
Pictures taken using the "Photo Mode" functionality of the game are stored in your phone's gallery.
User-made content (aka mods) go to folder: "/android/data/com.evag.smx/files/mods/".
Track Editor levels are stored in this folder "/android/data/com.evag.smx/files/TrackEditor".
If you want to backup your progress, copy the save file "user1.save" located here "/android/data/com.evag.smx/files/user1.save" to somewhere safe in your device. later you can copy it back to restore your progress.
Your internet connection is weak, the Unity Ads server is down or you are blocking the unity ads servers, check your internet connection whitelist the game from your adblocker, and try relaunching the game.
The game works best on 4 GB of RAM or more devices, devices with less memory RAM may crash due to instability. Try to close background running apps.