File "electrum\gui\qt\transaction_dialog.py", line 212, in save
  File "electrum\gui\qt\main_window.py", line 3214, in save_transaction_into_wallet
  File "electrum\util.py", line 336, in <lambda>
  File "electrum\util.py", line 332, in do_profile
  File "electrum\address_synchronizer.py", line 431, in save_transactions
  File "electrum\util.py", line 336, in <lambda>
  File "electrum\util.py", line 332, in do_profile
  File "electrum\storage.py", line 107, in write
  File "electrum\storage.py", line 115, in _write
  File "json\__init__.py", line 238, in dumps
  File "json\encoder.py", line 201, in encode
  File "json\encoder.py", line 430, in _iterencode
  File "json\encoder.py", line 404, in _iterencode_dict
  File "json\encoder.py", line 353, in _iterencode_dict