migrating reftypes from V6 to V7

How do I migrate my reftype-definitions from V6 to V7?
When I simply copy the old reftypes folder to the new V7 directory, I get an error message:
"List index out of bounds (-1)"
Thanks

Because there are database

Because there are database table fields name changes and new fields added, so you cannot copy version 6 reftypes files to version 7 installation. Please redo the customization in version 7.