diff -u b/core/modules/forum/config/optional/views.view.forum_forums.yml b/core/modules/forum/config/optional/views.view.forum_forums.yml
--- b/core/modules/forum/config/optional/views.view.forum_forums.yml
+++ b/core/modules/forum/config/optional/views.view.forum_forums.yml
@@ -16,7 +16,6 @@
 tag: ''
 base_table: taxonomy_term_field_data
 base_field: tid
-core: 8.x
 display:
   default:
     display_plugin: default
@@ -724,14 +723,6 @@
           date_format: fallback
           custom_date_format: ''
           timezone: ''
-          set_precision: false
-          precision: 0
-          decimal: .
-          separator: ''
-          format_plural: 0
-          format_plural_string: "1\x03@count"
-          prefix: ''
-          suffix: ''
           plugin_id: comment_last_timestamp
       filters:
         vid: