I've just downloaded the application from Software Informer on a 64-bit Windows 10 PC and I didn't encounter any errors during the installation process. I've even played it for about seven minutes without a single error. Additionally, I can't find any mention of similar incidents online, which is rather weird.
As you probably know, the free version of Fishdom has a 60 minutes time limit and if you want to play more, you have to buy the game, so those errors may be caused by you playing it for over one hour on your PC. If that's not the case, try disabling your download manager in case you have one or downloading the game directly from its official website and maybe that will help solve your problem. Lastly, try using an application like CCleaner to clean your Windows registry.