MATLAB---simulink的菜单/工具条丢失
遇到如图问题：
可能是由于删除了路径，解决方式如下：
1. Refresh the file system caches using the following commands:
>> restoredefaultpath
>> rehash toolboxcache
2. Run the following command to rebuild Simulink and Library menus and toolbars:
>> sl_refresh_customizations
3. Close all the instance of MATLAB and then restart.
附上原答案地址：https://www.mathworks.com/matlabcentral/answers/323926-menu-bar-missing-in-simulink