fix #3508

lib/base_wizard.py

@@ -234,6 +234,15 @@ class BaseWizard(object):
         self.plugin = self.plugins.get_plugin(name)
         try:
             self.plugin.setup_device(device_info, self, purpose)
+        except OSError as e:
+            self.show_error(_('We encountered an error while connecting to your device:')
+                            + '\n' + str(e) + '\n'
+                            + _('To try to fix this, we will now re-pair with your device.') + '\n'
+                            + _('Please try again.'))
+            devmgr = self.plugins.device_manager
+            devmgr.unpair_id(device_info.device.id_)
+            self.choose_hw_device(purpose)
+            return
         except BaseException as e:
             self.show_error(str(e))
             self.choose_hw_device(purpose)

lib/plugins.py

@@ -362,15 +362,20 @@ class DeviceMgr(ThreadJob, PrintError):
             if not xpub in self.xpub_ids:
                 return
             _id = self.xpub_ids.pop(xpub)
-        client = self.client_lookup(_id)
-        self.clients.pop(client, None)
-        if client:
-            client.close()
+            self._close_client(_id)
 
     def unpair_id(self, id_):
         xpub = self.xpub_by_id(id_)
         if xpub:
             self.unpair_xpub(xpub)
+        else:
+            self._close_client(id_)
+
+    def _close_client(self, id_):
+        client = self.client_lookup(id_)
+        self.clients.pop(client, None)
+        if client:
+            client.close()
 
     def pair_xpub(self, xpub, id_):
         with self.lock:

plugins/ledger/ledger.py

@@ -172,6 +172,10 @@ class Ledger_Client():
                 raise Exception("Dongle is temporarily locked - please unplug it and replug it again")
             if ((e.sw & 0xFFF0) == 0x63c0):
                 raise Exception("Invalid PIN - please unplug the dongle and plug it again before retrying")
+            if e.sw == 0x6f00 and e.message == 'Invalid channel':
+                # based on docs 0x6f00 might be a more general error, hence we also compare message to be sure
+                raise Exception("Invalid channel.\n"
+                                "Please make sure that 'Browser support' is disabled on your device.")
             raise e
 
     def checkDevice(self):