I already did this thrice. I wrote that I even cleaned up not just the game directory, but even the %appdata%/Strive folder. It did not work.
I have found the reason of the problem after I used the debug .exe (the so-called "debug mod") and looked up the logs output. It seems from the code of the extension, that the folder of the extension in `%appdata%/strive/mods` must be called `AricsExpansion` without any version suffix. After the unpacking from the distrib archive the folder is called `AricsExpansion-1.8d` which completely 100% breaks the game startup.