[supervisor.hassos] Can't fetch versions

Installation Home Assistant OS
1

Hi,
I have this problem:

20-03-27 10:46:18 INFO (MainThread) [supervisor.hassos] Fetch OTA update from https://github.com/home-assistant/operating-system/releases/download/3.12/hassos_rpi3-3.12.raucb
20-03-27 10:48:31 WARNING (MainThread) [supervisor.hassos] Can't fetch versions from https://github.com/home-assistant/operating-system/releases/download/3.12/hassos_rpi3-3.12.raucb: 
20-03-27 10:48:31 ERROR (MainThread) [asyncio] Task exception was never retrieved
future: <Task finished coro=<HassOS.update() done, defined at /usr/src/supervisor/supervisor/hassos.py:150> exception=HassOSUpdateError()>
Traceback (most recent call last):
  File "/usr/src/supervisor/supervisor/hassos.py", line 161, in update
    int_ota = await self._download_raucb(version)
  File "/usr/src/supervisor/supervisor/hassos.py", line 111, in _download_raucb
    raise HassOSUpdateError()
supervisor.exceptions.HassOSUpdateError

My system is:

|arch |armv7l|
|---|---|
|dev |false|
|docker |true|
|hassio |true|
|os_name |Linux|
|os_version |4.19.93-v7|
|python_version |3.7.7|
|timezone |Europe/Rome|
|version |0.107.7|
|virtualenv |false|

and I have had this problem for a long time. Can you help me?