diff --git a/gui/qt/main_window.py b/gui/qt/main_window.py
index 3282fef40..35e88385f 100644
--- a/gui/qt/main_window.py
+++ b/gui/qt/main_window.py
@@ -2018,9 +2018,8 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         try:
             tx = tx_from_str(txt)
             return Transaction(tx)
-        except:
-            traceback.print_exc(file=sys.stdout)
-            self.show_critical(_("Electrum was unable to parse your transaction"))
+        except BaseException as e:
+            self.show_critical(_("Electrum was unable to parse your transaction") + ":\n" + str(e))
             return
 
     def read_tx_from_qrcode(self):
diff --git a/lib/transaction.py b/lib/transaction.py
index 0e4b6e0cb..16d701f44 100644
--- a/lib/transaction.py
+++ b/lib/transaction.py
@@ -896,6 +896,8 @@ def tx_from_str(txt):
     "json or raw hexadecimal"
     import json
     txt = txt.strip()
+    if not txt:
+        raise ValueError("empty string")
     try:
         bfh(txt)
         is_hex = True