I run FA for a small side business on a shared hosting server, can't get into all administrator settings. Not much of a coder
Was getting "Yellow Triangle" on many pages, anytime I changed a selector (ie customer)
Apparently they did some server-side upgrade ~ 1 yr ago and the only way I could operate with with javascript off (which is VERY clunky)
Every XHR from JSHttpRequest returned 403 error
I solved it today - in theory octet-stream isn't a whitelisted content type
Changed the request header to JSON and the issue went away
xr.setRequestHeader('Content-Type', 'application/json');
// Was 'application/octet-stream'
FYI -
The host is running Apache 2.4.58 and cpanel 110.0.17