Fix MM64178 (#30957)

Co-authored-by: Mattermost Build <build@mattermost.com>

server/i18n/en.json

@@ -575,6 +575,10 @@
     "id": "api.channel.update_channel_member_roles.scheme_role.app_error",
     "translation": "The provided role is managed by a Scheme and therefore cannot be applied directly to a Channel Member."
   },
+  {
+    "id": "api.channel.update_channel_member_roles.unset_user_scheme.app_error",
+    "translation": "Invalid channel member update: A channel member always has a user scheme."
+  },
   {
     "id": "api.channel.update_channel_member_roles.user_and_guest.app_error",
     "translation": "Invalid channel member update: A guest cannot be set for a single channel, a System Admin must promote or demote users to/from guests."
@@ -3390,6 +3394,10 @@
     "id": "api.team.update_team_member_roles.guest_and_user.app_error",
     "translation": "Invalid team member update: A user must be a guest or a user but not both."
   },
+  {
+    "id": "api.team.update_team_member_roles.unset_user_scheme.app_error",
+    "translation": "Invalid team member update: A team member always has a user scheme."
+  },
   {
     "id": "api.team.update_team_member_roles.user_and_guest.app_error",
     "translation": "Invalid team member update: A guest cannot be set for a single team, a System Admin must promote or demote users to/from guests."