Setting developer_mode error

Hello. I am having errors when I set “developer_mode”: 1 in site_config.json. Can someone help me? Here is a snip from my problem. Thanks!

Is your site_config.json looks like this,

{
 "db_name": "db_name", 
 "db_password": "db_password",
 "developer_mode": 1
}

if not please share fulll error screen shot.

Yes my config looked like that. Thank you for this. I don’t know why, but the problem was solved when I restarted the machine.