I decided to test my game outside the Editor. When I launched it several problems appeared: a) VolumetricFog turns from 1 to 0, b) The sun’s position is wrong, c) The physics don’t work. The speedboat and the boat on the far right swing in sync with the waves in the Editor. When I launched the game the boats remained stationary. Any help? Thank you.

Did you export to engine before switching to the GameLauncher? You can do this in the Sandbox by going to File->Export to Engine. Due to a bug that was only recently fixed it can also be that the Time of Day is set to the wrong value. Try checking the value that Time of Day is set to by typing e_TimeOfDay in the console. You can also set it to a different value with the same command, for exmaple by typing e_TimeOfDay 15.

1) First I checked the time at the console and I saw it was correct (6.45 in the morning).
2) Then I made the following changes: sys_Flash=0 | e_VolumetricFog=1 | r_DisplayInfo=0
Finally I Saved the Game and I pressed Export to Engine.
When I Launched the Game the time was incorrect; I have feeling that the program translated my time 6.45 am to 18.45 pm. The VolumetricFog was changed to 0, sys_Flash was changed to 1, the r_DisplayInfo was changed to 1, and the physics of the game did not work.

You can also open the console while in the game by pressing the ` key (the key next to the '1' key). In there you can also check the value of the Time of Day to make sure it's set to the right value.
To set the your variables (sys_Flash=0 | e_VolumetricFog=1 | r_DisplayInfo=0) to the right value you will have to set them in the project's configuration file.
If you're using the CRYENGINE 5.4 previews you can set your required variables in the cryproject file of your project. More information about how to add command variables to your project file can be found here.
If you're using CRYENGINE 5.3 you can add the variables to the Game.cfg file, which is located in your assets folder.

I tried to create a solution for my level and in the process the entire level got corrupted and I can’t open it anymore in the Editor. So, I will try to lounge a new game by creating a new level. Thank you.