Problem:
All of a sudden Office Web Apps Excel Web App stopped working and gave this Runtime error message on opening Microsoft Excel files from SharePoint 2013:
Server Error in '/x' Application.
![SharePoint Office Web Apps Server Error in '/x' Application]()
Solution:
This occurs due to the public key which connects to the WOPI application such as Office Web Apps Server to the SharePoint farm goes out of sync! To resolve the issue, Run from any SharePoint Server:
Update-SPWOPIProofKey![]()
All of a sudden Office Web Apps Excel Web App stopped working and gave this Runtime error message on opening Microsoft Excel files from SharePoint 2013:
Server Error in '/x' Application.
Solution:
This occurs due to the public key which connects to the WOPI application such as Office Web Apps Server to the SharePoint farm goes out of sync! To resolve the issue, Run from any SharePoint Server:
Update-SPWOPIProofKey