Android game crashes at first start (after installation)

Hello everyone, i’m receiving lots of complains from people who buy my Android game on google play that say the game crashes at the first start after installation. Other ones say they get slow fps at the first start. Why this happens? can you give me some advice? Thanks!

Here you will find some helpful info on why it might crash after launch:

The slow FPS could be because their phones are probably not up to it, e.g. your game is 3d and they have a low end phone. Or you might not have optimized your 2D game, and again they have a low end phone (e.g. you use many textures and you don’t use a texture atlas, so there are many draw calls – 1 for each texture, and hence low FPS). So, more info is needed to completely answer this part of the question, and maybe it needs to be a separate question from the “crash after launch” i.e. 2 separate issues.