Let’s Encrypt problem

Hallo together,
I have a problem with the Let’s Encrypt activation.
Wer is the problem, if I have this message.

Thanks

[ letsencrypt ] (Sun Oct 18 18:35:09 BST 2020)
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator webroot, Installer None
An unexpected error occurred:
Traceback (most recent call last):
File “/usr/lib/python3/dist-packages/josepy/interfaces.py”, line 176, in json_loads
loads = json.loads(json_string)
File “/usr/lib/python3.7/json/init.py”, line 348, in loads
return _default_decoder.decode(s)
File “/usr/lib/python3.7/json/decoder.py”, line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File “/usr/lib/python3.7/json/decoder.py”, line 355, in raw_decode
raise JSONDecodeError(“Expecting value”, s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

During handling of the above exception, another exception occurred:

josepy.errors.DeserializationError: Deserialization error: Expecting value: line 1 column 1 (char 0)
Please see the logfiles in /var/log/letsencrypt for more details.

Check the log file.
I guess there seems to be an issue with the certobt package.