diff --git a/electrum/gui/qt/main_window.py b/electrum/gui/qt/main_window.py
index 67fd252fd..c8d888495 100644
--- a/electrum/gui/qt/main_window.py
+++ b/electrum/gui/qt/main_window.py
@@ -1050,8 +1050,8 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger, QtEventListener):
         from .channel_details import ChannelDetailsDialog
         ChannelDetailsDialog(self, chan).show()
 
-    def show_transaction(self, tx: Transaction):
-        show_transaction(tx, parent=self)
+    def show_transaction(self, tx: Transaction, *, external_keypairs=None):
+        show_transaction(tx, parent=self, external_keypairs=external_keypairs)
 
     def show_lightning_transaction(self, tx_item):
         from .lightning_tx_dialog import LightningTxDialog
@@ -1174,7 +1174,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger, QtEventListener):
         invoice = self.wallet.get_invoice(key)
         if invoice and invoice.is_lightning() and invoice.get_address():
             if self.question(_('Payment failed') + '\n\n' + reason + '\n\n'+ 'Fallback to onchain payment?'):
-                self.send_tab.pay_onchain_dialog(self.get_coins(), invoice.get_outputs())
+                self.send_tab.pay_onchain_dialog(invoice.get_outputs())
         else:
             self.show_error(_('Payment failed') + '\n\n' + reason)
 
@@ -2387,6 +2387,9 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger, QtEventListener):
 
 
     def sweep_key_dialog(self):
+        if not self.network:
+            self.show_error(_("You are offline."))
+            return
         d = WindowModalDialog(self, title=_('Sweep private keys'))
         d.setMinimumSize(600, 300)
         vbox = QVBoxLayout(d)
@@ -2450,7 +2453,8 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger, QtEventListener):
             coins, keypairs = result
             outputs = [PartialTxOutput.from_address_and_value(addr, value='!')]
             self.warn_if_watching_only()
-            self.send_tab.pay_onchain_dialog(coins, outputs, external_keypairs=keypairs)
+            self.send_tab.pay_onchain_dialog(
+                outputs, external_keypairs=keypairs, get_coins=lambda *args, **kwargs: coins)
         def on_failure(exc_info):
             self.on_error(exc_info)
         msg = _('Preparing sweep transaction...')
diff --git a/electrum/gui/qt/send_tab.py b/electrum/gui/qt/send_tab.py
index c8276c82d..dffa15d31 100644
--- a/electrum/gui/qt/send_tab.py
+++ b/electrum/gui/qt/send_tab.py
@@ -4,7 +4,7 @@
 
 import asyncio
 from decimal import Decimal
-from typing import Optional, TYPE_CHECKING, Sequence, List
+from typing import Optional, TYPE_CHECKING, Sequence, List, Callable, Any
 from urllib.parse import urlparse
 
 from PyQt5.QtCore import pyqtSignal, QPoint
@@ -238,14 +238,18 @@ class SendTab(QWidget, MessageBoxMixin, Logger):
             self,
             outputs: List[PartialTxOutput], *,
             nonlocal_only=False,
-            external_keypairs=None) -> None:
+            external_keypairs=None,
+            get_coins: Callable[..., Sequence[PartialTxInput]] = None,
+    ) -> None:
         # trustedcoin requires this
         if run_hook('abort_send', self):
             return
         is_sweep = bool(external_keypairs)
         # we call get_coins inside make_tx, so that inputs can be changed dynamically
+        if get_coins is None:
+            get_coins = self.window.get_coins
         make_tx = lambda fee_est, *, confirmed_only=False: self.wallet.make_unsigned_transaction(
-            coins=self.window.get_coins(nonlocal_only=nonlocal_only, confirmed_only=confirmed_only),
+            coins=get_coins(nonlocal_only=nonlocal_only, confirmed_only=confirmed_only),
             outputs=outputs,
             fee=fee_est,
             is_sweep=is_sweep)
@@ -266,7 +270,7 @@ class SendTab(QWidget, MessageBoxMixin, Logger):
             return
         is_preview = conf_dlg.is_preview
         if is_preview:
-            self.window.show_transaction(tx)
+            self.window.show_transaction(tx, external_keypairs=external_keypairs)
             return
         self.save_pending_invoice()
         def sign_done(success):
diff --git a/electrum/gui/qt/transaction_dialog.py b/electrum/gui/qt/transaction_dialog.py
index 5fb1f2060..c29de2cbb 100644
--- a/electrum/gui/qt/transaction_dialog.py
+++ b/electrum/gui/qt/transaction_dialog.py
@@ -372,10 +372,15 @@ class TxInOutWidget(QWidget):
         menu.exec_(global_pos)
 
 
-
-def show_transaction(tx: Transaction, *, parent: 'ElectrumWindow', prompt_if_unsaved=False):
+def show_transaction(
+    tx: Transaction,
+    *,
+    parent: 'ElectrumWindow',
+    prompt_if_unsaved: bool = False,
+    external_keypairs=None,
+):
     try:
-        d = TxDialog(tx, parent=parent, prompt_if_unsaved=prompt_if_unsaved)
+        d = TxDialog(tx, parent=parent, prompt_if_unsaved=prompt_if_unsaved, external_keypairs=external_keypairs)
     except SerializationError as e:
         _logger.exception('unable to deserialize the transaction')
         parent.show_critical(_("Electrum was unable to deserialize the transaction:") + "\n" + str(e))
@@ -383,13 +388,11 @@ def show_transaction(tx: Transaction, *, parent: 'ElectrumWindow', prompt_if_uns
         d.show()
 
 
-
-
 class TxDialog(QDialog, MessageBoxMixin):
 
     throttled_update_sig = pyqtSignal()  # emit from thread to do update in main thread
 
-    def __init__(self, tx: Transaction, *, parent: 'ElectrumWindow', prompt_if_unsaved, external_keypairs=None):
+    def __init__(self, tx: Transaction, *, parent: 'ElectrumWindow', prompt_if_unsaved: bool, external_keypairs=None):
         '''Transactions in the wallet will show their description.
         Pass desc to give a description for txs not yet in the wallet.
         '''