AR System Message Catalog
ARERR  Cannot index a diary field, an unlimited length field, or a field with a maximum length over 255 bytes.
- AR System server
- Server messages and notifications
Fields that have lengths longer than 255 bytes (including diary fields and unlimited length character fields) cannot be indexed. You specified an index that includes a field that meets these criteria. If the index is a multiple-field index, you can still create the index if you remove the field that is not allowed.