Builder in Code Mode is not available

Your software
My Mautic version is: v4.4.9
My PHP version is: 7.4
My Database type and version is: 10.3.38-MariaDB

Your problem
My problem is:

“Builder” button is not active when Code Mode template is selected.

These errors are showing in the log:

No errors in the log

Steps I have tried to fix the problem:

Enabled GrapeJS plugin

I think that is how it is supposed to be. To create an email in code mode click into the advanced tab to access the HTML code editor.

Thats strange, because it says otherwise in Documentation and its definitely handy to have code on one side and preview next to it

With HTML editor I can not see any previews

You can choose a template, and use codemode there