Thanks for the PR. It sounds like your server is outputting an HTTP header in an unexpected format. Can you provide a list of the headers in the response so we can see what's up?

Hello, I found the issue.
There was a header set without a value, from a php snippets plugin.

This still could be useful here, since a header without a value will not break anything, why have it break qm

array (size=3)
0 => string 'X-Powered-By: PHP/8.0.27' (length=24)
1 => string 'Sample-Header-No-Value' (length=22)
2 => string 'Test: Value' (length=11)

this will break QM and wp-admin pages where Sample header exists

@johnbillion Although the RFC mandate a header value, I'm not sure if the application should break if there is a header without a value.

So our problem is fixed by fixing the header, so it's up to you how you want to treat this 🤖

Thanks, I'll make some adjustments to the header handling to handle this.