OSError: [Errno 28] No space left on device

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "electrum\gui\qt\settings_dialog.py", line 454, in on_currency
  File "electrum\exchange_rate.py", line 562, in set_enabled
  File "electrum\simple_config.py", line 171, in set_key
  File "electrum\simple_config.py", line 180, in _set_key_in_user_config
  File "electrum\simple_config.py", line 273, in save_user_config
OSError: [Errno 28] No space left on device