Two sign-in blockers: a false "device service is missing" on Windows in other languages (#13), and Apple error -23782 "a Mac with macOS 10.13 or later is required" (#14).
#13: "Apple's device service is missing" on a non-English Windows. iPASide read the service state from the text of sc query, which Windows translates (STATO instead of STATE on an Italian system), so a running Apple Mobile Device Service looked missing and iPASide told the person to reinstall iTunes. It now asks the Windows service manager directly, which has no language; the sc fallback reads the state number and name rather than the label. Thanks to @alias85 for the root cause and the one-line workaround.
#14: Apple error -23782. Every public anisette service describes a Mac running Mac OS X 10.12.6. For some Apple Accounts Apple now refuses that at the first sign-in step ("A Mac with macOS version 10.13 or later is required"). Many iloader users report the same error. iPASide now answers that one error by presenting a newer Mac identity (the same MacBookPro13,3 hardware, on macOS 13.6.7) and asking again, for the rest of that sign-in and afterwards. Accounts that sign in today are never switched, because the newer identity is only used after Apple asks for it. If Apple refuses it too, the message says so.
Also: the message shown with the code box after a refused text message no longer says "wait a few minutes" twice.
Verified. 726 engine tests and 799 app tests pass; each of 20 deliberate breaks of the new logic was caught by a test. #13: checked against the real Windows service manager (a running service, a missing one, and the Apple device service) and against Italian, German and French sc query output. #14: Apple accepts the newer identity at the first sign-in step (checked with an Apple ID that does not exist, so no real account was involved). The installer was built clean and verified itself when installed.
Not verified. #13 on an actual non-English Windows. #14 against an account that really gets -23782, so whether the newer identity is enough for such an account is still open; the sign-in steps after the first were not run with it. Nothing involving a connected iPhone was checked for this build. The text-message 403 in #12 is unchanged: it is Apple refusing the whole second step for that account.
The installer is unsigned, so SmartScreen will warn — the SHA-256 is in SHA256SUMS.txt.