MFEs fail when MFE_HOST is not a subdomain of LMS_HOST

How to reproduce the bug:

you have in your settings. everything works and MFEs will be available at
but when you set, MFEs are no longer functional (when you’re logged in) and this error will show up in the console logs:

I’m not an expert on openedx, but I dug a little more and I believe it has something to do with the LMS Login system and Frontend-Platform.
Am I missing something?

os Ubuntu 22.04
tutor-mfe v15.0.6
tutor v15.3.6


Yes this is a very common probelm, and can be reoslved by settings a settings that would make the cookie origin/domain as the root domain of the lms.

Here is an example/answer When attempting to enter a course's home on Learning MFE, Error: getLocale called before configuring i18n - #13 by ghassan.

Also here is dedicated tutor issue about it as well as preview: Preview mode breaks in Maple if PREVIEW_LMS_HOST is not a subdomain of LMS_HOST · Issue #557 · overhangio/tutor · GitHub.

1 Like

Thanks @ghassan. I used the lms-env patch and fixed the issue Mvelut mentioned here