when i want to get the facebook user's avatar through this url:/?asid=9340209919407118&height=600&width=600&ext=1744416129&hash=xxx on my Go program through http get . Then i receive this: {"title":"Invalid API Version Request","detail":"The API version provided in the request is not supported. Please ensure the version string follows the format MAJOR.MINOR.PATCH. Verify the version and try again.","status":400}. the xxx is to protect user privacy, i replaced the origina hash value.

After I get this response，i try it again. Seems to be working again. But i want know why？ I would be very grateful if you could help me solve this problem