diff --git a/electrum/gui/qt/send_tab.py b/electrum/gui/qt/send_tab.py
index c07851daf..bde4847f2 100644
--- a/electrum/gui/qt/send_tab.py
+++ b/electrum/gui/qt/send_tab.py
@@ -399,6 +399,7 @@ class SendTab(QWidget, MessageBoxMixin, Logger):
 
     def get_message(self):
         return self.message_e.text()
+
     def read_invoice(self) -> Optional[Invoice]:
         if self.check_payto_line_and_show_errors():
             return
@@ -410,7 +411,7 @@ class SendTab(QWidget, MessageBoxMixin, Logger):
         invoice = self.payment_identifier.get_invoice(self.wallet, amount_sat, self.get_message())
         #except Exception as e:
         if not invoice:
-            self.show_error('error getting invoice' + pi.error)
+            self.show_error('error getting invoice' + self.payment_identifier.error)
             return
         if not self.wallet.has_lightning() and not invoice.can_be_paid_onchain():
             self.show_error(_('Lightning is disabled'))
@@ -533,9 +534,10 @@ class SendTab(QWidget, MessageBoxMixin, Logger):
                 #               for err in errors]))
             return True
 
-        if self.payment_identifier.warning:
-            msg += '\n' + _('Do you wish to continue?')
-            if not self.question(msg):
+        warning = self.payment_identifier.warning
+        if warning:
+            warning += '\n' + _('Do you wish to continue?')
+            if not self.question(warning):
                 return True
 
         if self.payment_identifier.has_expired():
diff --git a/electrum/payment_identifier.py b/electrum/payment_identifier.py
index cbf1a6461..9172248d0 100644
--- a/electrum/payment_identifier.py
+++ b/electrum/payment_identifier.py
@@ -1,17 +1,18 @@
 import asyncio
 import urllib
 import re
-from decimal import Decimal
+from decimal import Decimal, InvalidOperation
 from typing import NamedTuple, Optional, Callable, Any, Sequence
 from urllib.parse import urlparse
 
 from . import bitcoin
+from .i18n import _
 from .logging import Logger
 from .util import parse_max_spend, format_satoshis_plain
 from .util import get_asyncio_loop, log_exceptions
 from .transaction import PartialTxOutput
 from .lnurl import decode_lnurl, request_lnurl, callback_lnurl, LNURLError, LNURL6Data
-from .bitcoin import COIN, TOTAL_COIN_SUPPLY_LIMIT_IN_BTC
+from .bitcoin import COIN, TOTAL_COIN_SUPPLY_LIMIT_IN_BTC, opcodes, construct_script
 from .lnaddr import lndecode, LnDecodeException, LnInvoiceException
 from .lnutil import IncompatibleOrInsaneFeatures
 
@@ -351,7 +352,7 @@ class PaymentIdentifier(Logger):
         p = pow(10, self.config.get_decimal_point())
         try:
             return int(p * Decimal(x))
-        except decimal.InvalidOperation:
+        except InvalidOperation:
             raise Exception("Invalid amount")
 
     def parse_address(self, line):