Hi,
I have just done a fresh install of Hassio on my brand new RPI4.
everything went OK until I wanted to add some add-on, like ssh server. I selected Supervisor==>Add-on Store and the blue donut is rolling forever. No addon is coming on this page.
I have restarted Hassio, but this did not change the game.
At some point I got this in the log file, not sure this is linked as after the reboot I no longer see such message coming again …
20-12-27 01:17:12 INFO (MainThread) [supervisor.store.git] Update add-on https://github.com/home-assistant/addons repository
20-12-27 01:17:12 ERROR (MainThread) [supervisor.jobs] Unhandled exception: ‘NoneType’ object has no attribute ‘active_branch’
Traceback (most recent call last):
File “/usr/src/supervisor/supervisor/jobs/decorator.py”, line 61, in wrapper
return await self._method(*args, **kwargs)
File “/usr/src/supervisor/supervisor/store/git.py”, line 143, in pull
branch = self.repo.active_branch.name
AttributeError: ‘NoneType’ object has no attribute ‘active_branch’
20-12-27 01:17:12 ERROR (MainThread) [asyncio] Task exception was never retrieved
future: <Task finished name=‘Task-1919’ coro=<Repository.update() done, defined at /usr/src/supervisor/supervisor/store/repository.py:101> exception=JobException()>
Traceback (most recent call last):
File “/usr/src/supervisor/supervisor/jobs/decorator.py”, line 61, in wrapper
return await self._method(*args, **kwargs)
File “/usr/src/supervisor/supervisor/store/git.py”, line 143, in pull
branch = self.repo.active_branch.name
AttributeError: ‘NoneType’ object has no attribute ‘active_branch’
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File “/usr/src/supervisor/supervisor/store/repository.py”, line 105, in update
await self.git.pull()
File “/usr/src/supervisor/supervisor/jobs/decorator.py”, line 67, in wrapper
raise JobException() from err
supervisor.exceptions.JobException
20-12-27 01:17:12 INFO (MainThread) [supervisor.store] Loading add-ons from store: 0 all - 0 new - 0 remove
Thanks in advance for your help. 
