wp-admin honors style-sheet <=> 'SCRIPT_DEBUG' is true.

[cjm51213]

Newly installed 6.6.2. Front-end requests worked fine. /wp-admin requests, by contrast, were css-free. For example, /wp-admin/wp-site-editor.php reported that javascript was not enabled and Firefox clearly showed that it was.

"define( 'SCRIPT_DEBUG', false );" problem.
"define( 'SCRIPT_DEBUG', true );" No problem.

I'm pretty sure that there is a defective dependancy and 'SCRIPT_DEBUG' compensates for it. My unfounded suspicion is that jQuery was not being loaded. No jQuery could look exactly like no javascript.

[cjm51213]

I have subsequently learned that independently of SCRIPT_DEBUG setting, define('CONCATENATE_SCRIPTS', false ); will also prevent this problem.

To summarize: "C" is CONCATENATE_SCRIPTS; "S" is SCRIPT_DEBUG

 C | S |
 T   T : Works
 T   F : Fails
 F   T : Works
 F   F : Works

If CONCATENATE_SCRIPTS is true, then nothing else has any effect. If CONCATENATE_SCRIPTS is false, then SCRIPT_DEBUG is controlling.