The cumulative lengths of the columns specified in the exact match joins exceeds the 900 byte limit for index keys. Fuzzy ...

The cumulative lengths of the columns specified in the exact match joins exceeds the 900 byte limit for index keys.  Fuzzy Lookup creates an index on the exact match columns to increase lookup performance and there is a possibility that creation of this index may fail and the lookup will fall back to an alternative, possibly slower, method of finding matches. If performance is a problem, try removing some exact match join columns or reduce the maximum lengths of variable length exact match columns.