Error: .htaccess: Invalid command '\xef\xbb\xbfRewriteEngine', perhaps misspelled or defined by a module not included in the server configuration
This error is because of the invisible junk characters in the .htaccess file. The characters \xef\xbb\xbf are called as Unicode BOM and are junk characters for Apache. So its throwing the above error on browser. This is usually happens on editing file from Windows systems especially using notepad.
In-order to solve this problem open the file in any Linux file editor and remove those junk characters. In case of using Windows notepad for file edit, make sure to save without BOM.