[Koha] MARC check...didn't pass the test

I'm not exactly sure how the mailing list works. I'm totally new to Koha. But I have encountered something I'm a bit confused by, and I thought maybe someone has seen this before and could tell me what they did to remedy the situation. I've done my MARC check and it recorded one error. It says: Item fields ALL items fields MUST: Be mapped to the same tag, And they must all be in the 10 (items) tab Any advice? Katie Christian Resource Center Berlin, Germany