When importing a ZIP archive, the Import Rules/Data tool stops with the message:
Encountered the following error: Class ZZZZZ does not exist
Beginning with V5.3, additional validation occurs during import operations. Rules which reference Rule-Obj-Class rules that do not exist on the target system cannot be imported.
This validation also applies to the classes listed on the Pages and Classes tabs. The improved validation prevents rules that reference non-existing classes from being loaded to the target system.
To address the issue, either create the missing Rule-Obj-Class rules in the target system and import the ZIP file again, or correct the Zip file.