First question, did you modify ANY (Can be as simple as changing a letter in a file) of the mod files? If no, then try verifying your game's files.
I usually get this error when I change values of mods, the issue with this is that when you choose mods using the in-game Host function, the game grabs the mods from the workshop thus causing a mismatch of your mods and the downloaded mods.
To fix this, I recommend uninstalling the mod of concern, exit the game, then reinstall the mod. (It seems that your error doesn't seem to spit out the mod file directory but rather to the base game files so I recommend checking the file integrity.)
I am not sure what all mods you have aside form the 3 map mods you've listed, but I use Blackwood and Pitstop and neither of the two gives me an error, so I assume Ekron may be the issue however I do not know what other mods you have.
