Syntax error when loading updated office.js in Outlook 2016 with IE11

[qystaubai]

Starting today an error occurs when office.js loads in older Outlook client like 2016 that uses IE11.

Office.js is loaded using CDN https://appsforoffice.microsoft.com/lib/1.1/hosted/office.js

SCRIPT1002: Syntax error office.js (80; 15) the line is var oteljs;(()=>{"use strict";

SCRIPT5009: Office not defined the line is Office.onReady(...)

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Your Environment

• Platform [PC desktop, Mac, iOS, Office on the web]: PC desktop
• Host [Excel, Word, PowerPoint, etc.]: Outlook
• Office version number: 2016
• Operating System: Windows 10
• Browser (if using Office on the web): -

Expected behavior

Office js should not give syntax errors and run on IE11

Current behavior

I believe it has to do with with arrow functions () => that are not transpiled and cannot run on IE11

Steps to reproduce

1. Run any web add-in in Outlook 2016 that uses IE11

[ChenNima]

The issue also occurs for Word, Office 2016 on WIndows.

[ndreisg]

This issue also occurs in Excel 2016 and was reported by multiple customers. I reproduced it with Excel 2016 VLSC. I assume the customers also have VLSC.

[theusner-thing]

Seeing that as well since today in Outlook 2016 with IE11

[JackDallSoelbeck]

Seeing issues loading Dynamics CRM app for Outlook today that could be related to this issue. It gives this error that normally means it can't load office.js: "Error: window.Office not available"

https://learn.microsoft.com/en-us/troubleshoot/dynamics-365/sales/dynamics-365-app-outlook-did-not-load

[els-ts]

We also got reports from our users with the Word 2019 volume license (using IE as add-in engine).

Update: We've did quick investigation on our side and have exactly same error in Word, from office.js (80, 15)

@exextoc - can you update flag that this affects all Office applications that are using IE11 as their engine?

[atsopuronen]

Our Outlook 2016 customers are also affected by this. They are reporting about Task Pane getting stuck at loading, and the underlying error is "Office" in undefined" and/or "OfficeRuntime" is undefined.

[xTNTx666]

Our Outlook 2016 customers are also affected by this. They are reporting about Task Pane getting stuck at loading, and the underlying error is "Office" in undefined" and/or "OfficeRuntime" is undefined.

The same with our customers who use Trinity in Outlook

[onestep]

@exextoc is there any workaround for now? Would installation of WebView2 and registry change described in Understanding the Office Add-ins runtime article help for users of non-Office365 versions of Outlook?

[darren-pex]

The same with our customers who use Trident in Outlook on both 2016 and 2019 (VL), is there an ETA on a fix or rollback?

https://learn.microsoft.com/en-us/office/dev/add-ins/concepts/browsers-used-by-office-web-add-ins#perpetual-versions-of-office-on-windows

[billzeman]

we are seeing this also. Looking at the office.js file it looks like it's using arrow notation and throwing syntax errors in IE11

[carlcarlsoniv]

Same issue. Word 2016/2019 versions that load IE11 can no longer load some add-ins.

[awelters]

Our Excel add in is no longer working in Windows Desktop Excel 2019 using IE 11. This breaks the promise that we can have add ins work with that platform/browser. Super disappointing as that is still used in Corporate America.

[BrentonWildes]

Also had this problem today. Solved it by switching from the CDN to a locally hosted copy of the files. I grabbed them via npm per the instructions on the main page here. The office.js file is in the /dist/ folder, you just need to load the entire folder to your project and switch your script CDN declaration to use it instead. Something like: <script src="/js/office-js/dist/office.js">

Hope this helps someone out there!

[ndreisg]

@exextoc is there any workaround for now? Would installation of WebView2 and registry change described in Understanding the Office Add-ins runtime article help for users of non-Office365 versions of Outlook?

Installing WebView2 would probably work for Office 2019 and Office 2016 retail but not for Office 2016 VLSC.

[zacfarnsworth]

Hi all, so sorry about the issues you are facing! We have initiated a rollback of this update to office-js and are taking care to ensure IE11 compatibility with any future updates. The rollback should be completed soon - in the meantime, @BrentonWildes and @ndreisg are correct about these potential short-term workarounds.

[JackDallSoelbeck]

Any update on when this might be solved ?

[zacfarnsworth]

We completed the rollback to a stable version late last night. Please let me know if issues persist.

[JackDallSoelbeck]

Ok great, the customer has testet addin in Outlook for CRM and it is working now. Thanks

[PeterLanguage]

Thank you, here in the EU everything is working now, since this morning.