AttributeError: 'NoneType' object has no attribute 'add'

[TARS-bot]

Crash Report

This crash report was reported through the automatic crash reporting system 🤖

Traceback

  File "electrum/gui/qt/main_window.py", line 2575, in <lambda>
  File "electrum/gui/qt/main_window.py", line 153, in request_password
  File "electrum/gui/qt/main_window.py", line 2530, in do_sign

AttributeError: 'NoneType' object has no attribute 'add'

Reporter

This issue was reported by 4 user(s):

Electrum Version	Python Version	Operating System	Wallet Type	Locale	Stack
4.0.9	3.7.9 (default, Sep 11 2020, 17:18:37) [Clang 11.0.0 (clang-1100.0.33.17)]	Darwin-20.3.0-x86_64-i386-64bit	standard,imported	?	ℹ
4.1.2	3.7.10 (default, Mar 31 2021, 13:19:38) [Clang 11.0.0 (clang-1100.0.33.17)]	Darwin-18.7.0-x86_64-i386-64bit	imported	?	ℹ
4.1.5	3.7.9 (v3.7.9:13c94747c7, Aug 15 2020, 01:31:08) [Clang 6.0 (clang-600.0.57)]	Darwin-20.6.0-x86_64-i386-64bit	standard	?	ℹ
4.3.1	3.9.11 (v3.9.11:2de452f8bf, Mar 16 2022, 10:34:36) [Clang 6.0 (clang-600.0.57)]	macOS-10.16-x86_64-i386-64bit	2of2,standard	?	ℹ

Additional Information

The reporting user(s) did not provide additional information.

[SomberNight]

https://github.com/spesmilo/electrum/blob/ae15bccb8192532afc4908b43f68797cd6239fd6/electrum/gui/qt/main_window.py#L2530