add exception message

fet2020/finance/admin.py

@@ -185,14 +185,18 @@ class BillAdmin(admin.ModelAdmin):
         except Exception:
             return "-"
 
-        qrcode = helpers.make_epc_qr(
-            name=tmp.name,
-            iban=tmp.iban,
-            amount=obj.amount,
-            text=obj.purpose,
-            bic=tmp.bic,
-            encoding="utf-8",
-        )
+        try:
+            qrcode = helpers.make_epc_qr(
+                name=tmp.name,
+                iban=tmp.iban,
+                amount=obj.amount,
+                text=obj.purpose,
+                bic=tmp.bic,
+                encoding="utf-8",
+            )
+        except Exception:
+            return "Daten für QR Code ungültig"
+
         uri = qrcode.png_data_uri(scale=3.0)
         return format_html(f'<img src="{uri}">')