Hello everyone.
 
	Recently I've got the above browser error message in the middle of upgrading process (~/admin/upgrade/process/) from version 4.2.2
 
	The same message also appears if I'm trying to upgrade any core plugins in the admin dashboard.
 
	I'm using Apache 2.4.34 + PHP 5.6.36 + Mysql 5.7.22-cll-lve
 
	Can I have any solutions to fix this problem? Thanks.