Those items belong to the multiplayer's 'invasion mode' and are in the latest version of ModSys. What I don't understand is how you can have 'module_scripts' with the 'invasion mode' scripts and not have 'module_items' with those items, mmm, very strange.
Download the latest version again and be sure to check 'module_items', all items that now give id ERROR are at the end of the file.
Download page (other downloads section):
https://www.taleworlds.com/en/Games/Warband/Download