In surveys where the ability to save responses via name and password for later is enabled, those responses are saved in the responses table as "partial responses" (Completed = N) and also separately in another view - "Saved but not submitted" (admin/saved).

When such a survey is deactivated, it is unclear what happens to the identifiers and passwords of those "saved but not submitted" responses. The "partial response" is, however, retained.

When that deactivated survey responses table is re-imported once the survey is re-activated, the "saved but not submitted" identifiers/passwords are NOT re-imported. This means that any partial response that was in-progress is now "orphaned" - it can never be completed by the survey participant, and users that received "save for later" e-mails will receive errors if they use their credentials in an attempt to finish.