wordpress warning cannot modify header information – headers already sent by

「『php.ini』の設定を変えるといい」

「php.ini」の設定で「output_buffering = Off」となっていたら、「output_buffering = On」にする。

ロリポップ：

WEB ツール　→　PHP設定

Experienced again when japantourguide.net was attached to japantourguide.lolipop.jp.  Interestingly, although php.ini had been set correctly on japantourguide.lolipop.jp, I could not login into this already set site because the php.ini was not set correctly on newly attached japantourguide.net.