Sidebar is failing to load consistently making add-on non functional

Google Workspace Developers Q&A
,
1

My published add-ons for (EasyAccents) Docs and Slides have decided to stop working properly. With over 60 million installs I am trying to find some help here…

There were no code changes, but we are noticing that the sidebar is no longer launching consistently, and trying to navigate to any content within the sidebar (functions that utilize the createTemplateFromFile() and DocumentApp.getUi().showSidebar() seem to be failing and closing the sidebar.

Anyone else experiencing this and or have any idea if there is something wrong with app-script or something else going on (we have not had any code changes for quite some time).

Thanks,

2

Hey,

Hope you’re keeping well.

This behavior aligns with the recent rollout of stricter HTML sandboxing and sidebar rendering changes in Google Docs and Slides add-ons using Apps Script. When an add-on sidebar relies on HtmlService.createTemplateFromFile() and calls DocumentApp.getUi().showSidebar(), any template that includes scriptlets or dynamic client-side functions that violate the HTML Service sandbox mode will now fail silently and close. The issue is often triggered when the template references missing files or when the MIME type defaults to HtmlService.SandboxMode.IFRAME, which enforces tighter isolation.

To stabilize the sidebar, confirm that each HTML file loaded through createTemplateFromFile() is correctly published and that you explicitly set sandboxing with HtmlService.createHtmlOutputFromFile(‘Sidebar’).setSandboxMode(HtmlService.SandboxMode.IFRAME) or switch to EMBEDDED if you need inline execution. Review your manifest to ensure all files are listed and that the add-on uses the latest Apps Script runtime (V8). If the sidebar still collapses, test the script directly from the Apps Script editor using the “Run > Test as add-on” feature to capture runtime errors in the execution log, as outlined in Apps Script debugging documentation.

Thanks and regards,
Taz

3

I have tried this (this is actually how it was originally created, but most calls are failing.
example:

function showStart() {

var htmlTemplate = HtmlService.createTemplateFromFile(‘sidebar’);

var htmlOutput = htmlTemplate.evaluate()

 .setTitle('sidebar title') // Set the title of the sidebar .setSandboxMode(HtmlService.SandboxMode.IFRAME);

// Display the sidebar in the Document UI

DocumentApp.getUi().showSidebar(htmlOutput);

}

This will only launch sometimes… fails most times. Just started seeing this a couple of days ago.