I downloaded the huge 1GB download out of curiosity, hoping I could help. Calfuso - I can see that you have put many, many, many hours of effort into this - it's insane - the project is enormous. How long have you been working on it? Unfortunately it has some very big problems at a fundamental level, that will be extremely difficult to fix. I couldn't really make sense of anything in your event sheets as few of your assets have names and there are over 1000 of them, there appears to be many conflicting and redundant actions (one of these is probably causing your animation problems). One huge issue is that the game is not optimized in any way so it has huge filesize and even larger memory footprint - you basically need a supercomputer to run this well. I would very strongly suggest learning about optimization and starting again. What you want to achieve can be done in far less complicated ways, with far less events, far less assets, far less memory etc - if you continue doing it this way you will have a game that no one can play. I've had to scrap a few projects, it hurts, but as long as you can learn something from it - it's worth it.
Here are some links that I found very useful in helping to understand optimization:
https://www.scirra.com/blog/112/remember-not-to-waste-your-memory
https://www.scirra.com/blog/83/optimisation-dont-waste-your-time
https://www.scirra.com/manual/134/performance-tips
Sorry I couldn't fix your particular problem, but I really think learning more about optimization and starting again, while difficult now will make your life easier in the future and will make a better game too.