diff -Nru ubiquity-20.04.15.16/debian/changelog ubiquity-20.04.15.17/debian/changelog
--- ubiquity-20.04.15.16/debian/changelog	2021-07-26 15:13:38.000000000 +0000
+++ ubiquity-20.04.15.17/debian/changelog	2021-08-06 08:08:08.000000000 +0000
@@ -1,3 +1,11 @@
+ubiquity (20.04.15.17) focal; urgency=medium
+
+  [ Didier Roche ]
+  [ Jean-Baptiste Lallement ]
+  * Fixed crash message with manually created encrypted volumes
+
+ -- Didier Roche <didrocks@ubuntu.com>  Fri, 06 Aug 2021 10:08:08 +0200
+
 ubiquity (20.04.15.16) focal; urgency=medium
 
   * Automatic update of included source packages: shim-signed 1.40.6.
diff -Nru ubiquity-20.04.15.16/debian/ubiquity.templates ubiquity-20.04.15.17/debian/ubiquity.templates
--- ubiquity-20.04.15.16/debian/ubiquity.templates	2021-07-26 15:12:32.000000000 +0000
+++ ubiquity-20.04.15.17/debian/ubiquity.templates	2021-08-06 08:08:08.000000000 +0000
@@ -789,7 +789,7 @@
  installation will continue, but you may have to manually add the recovery
  key in the installed system with the command:
  .
- cryptsetup luksAddKey <device>
+ cryptsetup luksAddKey device_name
 
 Template: ubiquity/install/md5_check
 Type: boolean
diff -Nru ubiquity-20.04.15.16/scripts/plugininstall.py ubiquity-20.04.15.17/scripts/plugininstall.py
--- ubiquity-20.04.15.16/scripts/plugininstall.py	2021-07-26 15:12:32.000000000 +0000
+++ ubiquity-20.04.15.17/scripts/plugininstall.py	2021-08-06 08:08:08.000000000 +0000
@@ -909,6 +909,15 @@
 
         debconf_disk = self.db.get('partman-auto/select_disk')
         disk = debconf_disk.split('/')[-1].replace('=', '/')
+        if not disk:  # disk is not set in manual partitioning mode
+            syslog.syslog(
+                syslog.LOG_ERR,
+                'Determining installation disk failed. '
+                'Setting a recovery key is supported only with partman-auto.')
+            self.clean_crypto_keys()
+            self.db.input('critical', 'ubiquity/install/broken_luks_add_key')
+            self.db.go()
+            return
 
         args = ['lsblk', '-lp', '-oNAME,FSTYPE', disk]
         lsblk_out = subprocess.check_output(args).decode(sys.stdout.encoding)
diff -Nru ubiquity-20.04.15.16/ubiquity/plugins/ubi-partman.py ubiquity-20.04.15.17/ubiquity/plugins/ubi-partman.py
--- ubiquity-20.04.15.16/ubiquity/plugins/ubi-partman.py	2021-07-26 15:12:33.000000000 +0000
+++ ubiquity-20.04.15.17/ubiquity/plugins/ubi-partman.py	2021-08-06 08:08:08.000000000 +0000
@@ -462,6 +462,7 @@
             self.set_page_title(self.custom_partitioning.get_label())
             self.current_page = self.page_advanced
             self.move_crypto_widgets(auto=False)
+            self.recovery_key.set_text("")
             self.controller.go_to_page(self.current_page)
             self.controller.toggle_next_button('install_button')
             self.plugin_is_install = True