Why does the error 121 invalid hash occur when uploading audio to vk?

Question

Python

response after uploading audio to server : "{'redirect': ' vk.com/audio.php?act=done_add&mid=326786278&aid=0&... ', 'audio': '%7B%22audio%22%3A%229231d24629% 22%2C%22time%22%3A3%2C%22artist%22%3A%22%22%2C%22title%22%3A%22%22%2C%22genre%22%3A0%2C%22album%22%3A% 22%22%2C%22bitrate%22%3A48%2C%22bitrate_mode%22%3A%22cbr%22%2C%22md5%22%3A%22f539163ecaae014274a0d24bafe70f0c%22%2C%22kad%22%3A%220e00155a501f36cad029b%2fc04b% 22vkaf_gen_data%22%3A%7B%22key%22%3A%22fp326786278_9231d24629%22%2C%22res%22%3A%7B%22result%22%3Atrue%2C%22_%22%3A%22_%22%7D%2C% 22err%22%3A%5B%5D%7D%7D', 'hash': 'd13af9907cb3c5000d64d0120666c7ad', 'server': 611226}"
url_upload :"' https://pu.vk.com/c611226/upload.php? act=add_audio...'"
Here is a save request that results in a 121 invalid hash error. Please tell me what is wrong.
https://api.vk.com/method/audio.save?&audio=%7B%22...