Issue: After successful magento installation, as admin user when you try to login admin – the Loader will keep on load and it won’t be allow you to access the magento admin dashboard and admin pages.
Identify the Issue: Select inspect element from your browser, you may see below console error message,
static/adminhtml/Magento/backend/en_US/js-translation.json is not loading –> This file path may redirect you to 404 page when you open this file from your browser.
“Deploy static view files” command with your theme .
Still Issue ? : Copy this file from your lower/other environment (if already exist) and paste into your pub admin theme folder path by manually, (Note: Magento/backend/ is my backend theme)
Note: In-case if this file is not available in your lower environment, then you create by manually add  as content of the file and save the file name with “js-translation.json” and use it.