Per our follow-up with Salesforce team, this was confirmed to be an issue with Salesforce Authentication Service. The incident is currently reported on Salesforce Trust site at https://status.salesforce.com
“The Salesforce Technology Team is investigating an issue with Salesforce Authentication Services and exporting of Reports. Thank you for your patience and continued business”
This seems to have been resolved on its own for the majority of ClickDeploy customers. However, if you still experience the issue, please follow the progress on Salesforce trust site or contact Salesforce support team.
Thank you for your patience.