Troubleshooting the invalid manifest file error for PowerPoint and Excel add-ins

SYMPTOM 
“Invalid manifest file” error is displayed when deploying the add-in through the MSFT Admin Center. 

ACTION 
This is a known issue in Strategy One Update 11 (September 2023) release. Perform the following steps to fix the issue: 

• Open the generated XML in a text editor. 
• Search for element ‘Action’ with type ‘ShowTaskpane’ in the file
  

• Remove the line <TaskpaneId>Office.AutoShowTaskpaneWithDocument</TaskpaneId> from the xml file. 
  

• Save the changes and redeploy the file.
• Manifest file is now validated and does not throw any error.  

Strategy plans to publish a new version of Workstation that fixes this problem. This article will be updated when the new version is available in the download site.