Tor Messenger is not working on Windows XP
Going through the blog comments I found: https://blog.torproject.org/blog/tor-messenger-beta-chat-over-tor-easily#comment-113499 which basically says
Windows XP, instantbird.exe - entry point not found: "the procedure entry point _vsnprintf_s could not be located in the dynamic library msvcrt.dll"
This is basically the Tor Browser issue in #9084 (closed). So, it seems something goes wrong with the Windows cross-compilation.