File "electrum/util.py", line 882, in run_with_except_hook
  File "electrum/network.py", line 1085, in run
  File "electrum/network.py", line 1067, in wait_on_sockets
  File "electrum/network.py", line 719, in process_responses
  File "electrum/network.py", line 662, in process_response
  File "electrum/verifier.py", line 116, in verify_merkle
  File "electrum/address_synchronizer.py", line 437, in save_verified_tx
  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