We are unable to export Audit on test environment

Issue Summary

Not able to export Audit Logs from the Export button on UI. The download starts and it fails with the error "Failure: Network Error"

Steps to Reproduce

1. Go to link: https://<site>.atlassian.net/wiki/admin/auditlogging.action
2. Click 'Export'

Expected Results

Audit logs should get exported. If the logs are huge, it should take time.

Actual Results

The export fails sometimes within a minute with error "Failure: Network Error"

In the splunk logs we get the error message:

Could not map exception type java.lang.NullPointerException to a specific REST status. Defaulting to InternalServerError

stack: java.lang.NullPointerException: userkey
com.google.common.base.Preconditions.checkNotNull(Preconditions.java:228)
com.atlassian.sal.api.user.UserKey.<init>(UserKey.java:24)
com.atlassian.confluence.api.model.people.User$Builder.userKey(User.java:181)

Also, if we try further back in the audit logs from the UI, we get the below error after like 37th page:

Fetch of audit logs failed, please try again.

Workaround

Currently there is no known workaround for this behavior.