Unable to end impersonation or impersonate another user after impersonating non-admin userIssue After impersonating a non-admin user, the End Impersonation and Impersonate User options no longer work. The following can be seen in the node logs: WARNING *** WARNING *** Attempt made to impersonate a non-existent user: <sys_id>, returning null instead [REST API] RESTAPIProcessor : Cannot impersonate The following error can also be seen in the javascript console: POST https://<instance_name>.service-now.com/api/now/ui/impersonate/<sys_id> 400 (Bad Request)CauseThis can be caused by a before query business rule on the sys_user table. If the business rule is filtering out the user who is doing the impersonating, the above errors are thrown.ResolutionThe business rule causing the issue will need to be refactored or disabled. An ACL may be implemented in place of the 'before query' business rule.Related LinksSimilar issue: End Impersonation does not work for external users