hello i think i solved the cause of this problem.

when you restart the game after stopping The game has a specific layout that changes the order.

For example: If you install the Towers and pause the game in 500 waves. When you restart the game it will be different to gain the experience or power of the waves along with the characteristics of the tower and the game cannot start because the game cannot adjust the tower strengths gained in so many waves and so on.

Because the game's research network is very large and extremely research-capable, the skills of the towers (damage, attack speed, etc.) may not be able to be compensated due to excessive game waves. (Usually if the game restarts)

I solved this problem by investigating the structure of the game.

sometimes I play for 800 waves and then I can continue where I left without problems. FPS (Hardware) May cause problems, may be related to the overall performance of the game. God Day.