WHM/cPanel menu names replaced with "STR"

Symptoms

In WHM and cPanel, some menu items and headings display "STR" instead of the expected menu item or heading.

Description

The issue occurs when the English locale files have become corrupt.

Workaround

1. Access the server's command line as the 'root' user via SSH or "Terminal" in WHM.
2. Create a storage folder.

   mkdir /root/mvtarget

3. Move aside the en.cache file.

   mv -v /usr/local/cpanel/locale/en.cache /root/mvtarget/

4. Move aside the en.yaml file.

   mv -v /usr/local/cpanel/locale/en.yaml /root/mvtarget/

5. Move aside the en.cdb file.

   mv -v /var/cpanel/locale/en.cdb /root/mvtarget/

6. Rebuild the locale database.

   /usr/local/cpanel/bin/servers_queue queue build_locale_databases; /usr/local/cpanel/bin/servers_queue run