WordPress WP admin – cannot modify header information after wordpress update

Solution:

Ash, are you using any ftp software? if yes then change your file transfer type to binary as in FTP Client,

  • In Total Commander: locate ‘Transfer mode’ tab in tool bar on top. Then using drop-down selector click ‘Binary (archives, doc etc.)’
  • FileZilla: in top menu select Transfer> Transfer type> Binary
  • CuteFTP: navigate to File> Transfer Type> Binary

Refernce Link