The FixedVersion field is a reference field for incidents which denotes the version of the software/hardware the incident has been fixed in (there may be 0, 1 or many selections for this field per incident).
The value depends on what has been entered in the Fixed Version field picklist in Enterprise Tester. For example:
FixedVersion IN ["V1.0", "V2.0"]
Or just a single value:
FixedVersion = "version 1"
=, IN, !=, NOT IN, IS, IS NOT
|Aggregation||Yes (String Array)|