Forum Discussion
RaoulRSV
Sep 15, 2021Copper Contributor
Office-js addin with webapi in Api management. Failed to fetch
Hello. My application contains one office-js addin (typescript) project + one Webapi core (c#) project, both communicating through a fetch function when cors is enabled.It works together properly on ...
Kidd_Ip
Nov 27, 2025MVP
The “failed to fetch” error commonly encountered in Office.js add-ins deployed to Azure is typically caused by issues with HTTPS configuration or CORS policies.
Self-signed certificates are not supported in this context. Office add-ins require a trusted SSL certificate issued by a recognized Certificate Authority (CA). In addition, CORS must be correctly configured within Azure API Management, not just at the WebAPI level.
Requirements for running Office Add-ins - Office Add-ins | Microsoft Learn