My users complain about refused to connect error. How do I fix this?

If you are a G Suite addon developer and your users are complaining about " refused to connect" error, migrate your addon to apps script v8 engine. In the meantime, ask your users to sign in into one Gmail account at a time using incognito window.

1. How to solve this error permanently?

1. Open your Apps Script editor > Select View > Show project manifest.
2. In the appsscript.json manifest file, set the runtimeVersion field to the value V8.
3. Test your code for these migration incompatibilities:
4. Save it as a new version (under File > Manage versions) and deploy the new version in production.

2. How to solve this error while I am migrating to v8?

Share this article with your users that guides them step-by-step to solve this problem: