I have developed an Office 365 app using MEAN-JS - ie Express and Node.js. It runs fine on Excel Desktop environment, but when running on Excel's Web App environment I am getting this error while the app is loading into the frame:
Sys.ArgumentNullException: Value cannot be null. Parameter name: conversationId
File: excel-web-16.00.js, Line: 11, Column: 49669
From what I can research conversationId should be part of the API for mail apps, not Excel apps. So I am not sure why the Excel-Web-16.00.js API is looking for this parameter?
I've set up the test environment for Excel Web by loading the app manifest into an Office 365 Developer Sharepoint site, then running Excel Online and inserting the app.
Has anyone come across this before?
Thanks for your help.
