Error using Dexie from browser extension content scripts

Question

I'm facing an error when I run the Dexie Hello World from the content script of my firefox extension.

The extension is:

• in typescript
• compiled using webpack + babbel
• runned using web-ext run.

The previously linked example is declared in the manifest.json as content_scripts and the storage permission is set.

I think the problem is related to the extension environment , because when I paste the code compiled by webpack into the browser console it works a expected.

The error: OpenFailedError: TypeError "then" is read-only

Versions:

• Dexie.js: 3.0.3
• web-ext: 5.5.0
• firefox: 86.0

Thanks for the support!