After theme installation or updating, the menu and some other modules disappeared.
- You need to trigger the regeneration of the /cache/class_index.php file. This can be done simply by deleting the file.
- Turn off the “Disable all overrides” option on the “BO > Advanced parameters > Performance” page.
- Please check if the “Overriding default behaviors” module is properly installed. I can help you manually install it if it’s not properly installed, please send me your FTP access via the contact form below.
For more help, please mail me from my profile page.