Here echoing what @DoubleFishes said, and giving my full copy-paste with only MCT/VCO open through the Prop Joe's mod manager, as it was too long and I want to help:

"wolfy_vco" has been disabled due to an error while loading it. Report this issue to the mod author.
Filepath is script/mct/settings/vco.lua

Error: [string "script\groovy\modules\mct\objects\sections\obj.lua"]:71: Only alphanumerical characters and underscores are allowed in MCT keys!


stack traceback:
[string "script\groovy\modules\mct\main.lua"]:268: in function 'fail_func'
[string "script\_lib\mod\!glib_init.lua"]:316: in function 'load_modules'
[string "script\groovy\modules\mct\main.lua"]:259: in function 'load_mods'
[string "script\groovy\modules\mct\main.lua"]:48: in function <[string "script\groovy\modules\mct\main.lua"]:46>
[C]: in function 'pcall'
[string "script\groovy\modules\mct\main.lua"]:46: in function 'init'
[string "script\groovy\modules\mct\main.lua"]:634: in function <[string "script\groovy\modules\mct\main.lua"]:633>
[C]: in function 'pcall'
[string "script\groovy\modules\mct\main.lua"]:633: in function 'file'
[string "script\_lib\mod\!glib_init.lua"]:236: in function 'LoadModule'
[string "script\_lib\mod\!glib_init.lua"]:203: in function 'LoadInternalModules'
...
[string "script\_lib\lib_mod_loader.lua"]:116: in main chunk
[C]: in function 'require'
[string "script\all_scripted.lua"]:427: in function 'force_require'
[string "script\_lib\lib_header.lua"]:104: in main chunk
[C]: in function 'require'
[string "script\all_scripted.lua"]:427: in function 'force_require'
[string "script\all_scripted.lua"]:439: in function 'load_script_libraries'
[string "script\frontend\frontend_start.lua"]:11: in main chunk
[C]: in function 'require'
[string "script/frontend_scripted.lua"]:91: in main chunk