Adding account does nothing -- Runtime error on main thread. - Null check operator used on a null value and ** (business.braid.polycule:7897): WARNING **: 12:25:26.290: libsecret_error: 6\x83Č*\u007f, FormatException: Unexpected extension byte

I compiled the latest state of this git repository using this recipe (AUR package polycule-git) on Artix GNU/Linux (rolling release).

When I start polycule, I get libsecret related error messages:

package:media_kit_libs_linux registered.
[Matrix] Called main() with arguments: []

** (business.braid.polycule:7897): WARNING **: 12:25:26.290: libsecret_error: 6\x83Č*\u007f
[Matrix] Runtime error on main thread. - FormatException: Unexpected extension byte (at offset 1)
#0      _Utf8Decoder.convertSingle (dart:convert-patch/convert_patch.dart:1855)
#1      Utf8Decoder.convert (dart:convert/utf.dart:351)
#2      StandardMessageCodec.readValueOfType (package:flutter/src/services/message_codecs.dart:502)
#3      StandardMessageCodec.readValue (package:flutter/src/services/message_codecs.dart:477)
#4      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:645)
#5      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:370)
<asynchronous suspension>
#6      SettingsInterface.getTheme (package:polycule/src/utils/settings_interface.dart:14)
<asynchronous suspension>
#7      SettingsManager.initSettings (package:polycule/src/widgets/settings_manager.dart:34)
<asynchronous suspension>


** (business.braid.polycule:7897): WARNING **: 12:25:26.375: libsecret_error: f\xac\xfe\u001e(\u007f
[Matrix] Runtime error on main thread. - FormatException: Unexpected extension byte (at offset 1)
#0      _Utf8Decoder.convertSingle (dart:convert-patch/convert_patch.dart:1855)
#1      Utf8Decoder.convert (dart:convert/utf.dart:351)
#2      StandardMessageCodec.readValueOfType (package:flutter/src/services/message_codecs.dart:502)
#3      StandardMessageCodec.readValue (package:flutter/src/services/message_codecs.dart:477)
#4      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:645)
#5      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:370)
<asynchronous suspension>
#6      SettingsInterface.getTheme (package:polycule/src/utils/settings_interface.dart:14)
<asynchronous suspension>
#7      SettingsManager.initSettings (package:polycule/src/widgets/settings_manager.dart:34)
<asynchronous suspension>

Adding an account does not work; when I click in the Polycule main window on the "+" nothing happens, and in the terminal I get

[Matrix] Runtime error on main thread. - Null check operator used on a null value
#0      ClientManager._buildClient (package:polycule/src/widgets/matrix/client_manager/client_manager.dart:124)
#1      ClientStore.buildNewClient (package:polycule/src/widgets/matrix/client_manager/client_store.dart:226)
#2      ClientManager.addLoginClient (package:polycule/src/widgets/matrix/client_manager/client_manager.dart:111)
#3      AddClientButton.build.<anonymous closure> (package:polycule/src/widgets/matrix/client_manager/components/top/add_client_button.dart:19)
#4      _FutureCallbackBuilderState._operation (package:polycule/src/widgets/future_callback_builder.dart:43)
#5      _FutureCallbackBuilderState._callback.<anonymous closure> (package:polycule/src/widgets/future_callback_builder.dart:48)
#6      State.setState (package:flutter/src/widgets/framework.dart:1199)
#7      _FutureCallbackBuilderState._callback (package:polycule/src/widgets/future_callback_builder.dart:47)
#8      _InkResponseState.handleTap (package:flutter/src/material/ink_well.dart:1203)
#9      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:345)
#10     TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:737)
#11     BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:362)
#12     BaseTapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:293)
#13     PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:706)
#14     PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:97)
#15     PointerRouter._dispatchEventToRoutes.<anonymous closure> (package:flutter/src/gestures/pointer_router.dart:143)
#16     _LinkedHashMapMixin.forEach (dart:_compact_hash:764)
#17     PointerRouter._dispatchEventToRoutes (package:flutter/src/gestures/pointer_router.dart:141)
#18     PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:131)
#19     GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:530)
#20     GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:499)
#21     RendererBinding.dispatchEvent (package:flutter/src/rendering/binding.dart:473)
#22     GestureBinding._handlePointerEventImmediately (package:flutter/src/gestures/binding.dart:437)
#23     GestureBinding.handlePointerEvent (package:flutter/src/gestures/binding.dart:394)
#24     GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:341)
#25     GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:308)
#26     _rootRunUnary (dart:async/zone.dart:1546)
#27     _CustomZone.runUnary (dart:async/zone.dart:1429)
#28     _CustomZone.runUnaryGuarded (dart:async/zone.dart:1329)
#29     _invoke1 (dart:ui/hooks.dart:349)
#30     PlatformDispatcher._dispatchPointerDataPacket (dart:ui/platform_dispatcher.dart:467)
#31     _dispatchPointerDataPacket (dart:ui/hooks.dart:282)

Regards!