X_PATH_INVALID
Means
a path segment is not valid percent-encoding
Typical cause
a hand-built URL, or a value concatenated into a path instead of run through encodeURIComponent — %ZZ, a lone %, a truncated %A. Answers 400: the client wrote the path, so the client is who can fix it, and the request never reaches a handler
Fix
send the segment percent-encoded — encodeURIComponent(value); a literal % is %25