Active PHP Session Detected error

Hi there,

i was answering to mraamike topic, but you asked me to wrote a new one. here it is !

I have the folowing error and when i deactivate the wp cassify plugin, it disapear. Any idea ?

A PHP session was created by a session_start() function call. This interferes with REST API and loopback requests. The session should be closed by session_write_close() before making any HTTP requests.

[ Please do not bump. ]