How to remove all navigation menu from menu in suitecrm?
You can customize this file
themes/SuiteP/tpls/_headerModuleList.tpl
It’s not very direct, but in this line you can see a Smarty “if” to check if it is rendering the All menu:
https://github.com/salesagility/SuiteCRM/blob/master/themes/SuiteP/tpls/_headerModuleList.tpl#L281
You can adapt that to omit the menu entirely. Alternatively, you can customize CSS to hide that “All” class.