Topic
When running K2 for SharePoint Registration Wizard for SharePoint On-premises, you may run into (401) unauthorized error at the Application step if AppDeployment.exe hasn't been executed on SharePoint environment. For example, deploying the wrong K2 for SharePoint app from '..SetupSharePoint Online' folder to SharePoint On-premises app catalog will cause this issue.
Instructions
To get pass the issue, please delete the existing K2 for SharePoint app from SharePoint app catalog site and run AppDeployment.exe on a SharePoint Application server that includes the Central Administration server or at least with SharePoint Management Shell.
Additional Information