diff --git a/src/Umbraco.Cms.Api.Management/Factories/UserGroupPresentationFactory.cs b/src/Umbraco.Cms.Api.Management/Factories/UserGroupPresentationFactory.cs
index 0119864f5f..794cfa9bd9 100644
--- a/src/Umbraco.Cms.Api.Management/Factories/UserGroupPresentationFactory.cs
+++ b/src/Umbraco.Cms.Api.Management/Factories/UserGroupPresentationFactory.cs
@@ -1,11 +1,12 @@
-using Umbraco.Cms.Api.Management.Mapping;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Umbraco.Cms.Api.Management.Mapping;
 using Umbraco.Cms.Api.Management.ViewModels;
 using Umbraco.Cms.Api.Management.ViewModels.UserGroup;
-using Umbraco.Cms.Api.Management.ViewModels.UserGroup.Permissions;
 using Umbraco.Cms.Core;
+using Umbraco.Cms.Core.DependencyInjection;
 using Umbraco.Cms.Core.Models;
 using Umbraco.Cms.Core.Models.Membership;
-using Umbraco.Cms.Core.Models.Membership.Permissions;
 using Umbraco.Cms.Core.Services;
 using Umbraco.Cms.Core.Services.OperationStatus;
 using Umbraco.Cms.Core.Strings;
@@ -20,17 +21,30 @@ public class UserGroupPresentationFactory : IUserGroupPresentationFactory
     private readonly IShortStringHelper _shortStringHelper;
     private readonly ILanguageService _languageService;
     private readonly IPermissionPresentationFactory _permissionPresentationFactory;
+    private readonly ILogger<UserGroupPresentationFactory> _logger;
 
+    [Obsolete("Use the new constructor instead, will be removed in v16.")]
     public UserGroupPresentationFactory(
         IEntityService entityService,
         IShortStringHelper shortStringHelper,
         ILanguageService languageService,
         IPermissionPresentationFactory permissionPresentationFactory)
+    : this(entityService, shortStringHelper, languageService, permissionPresentationFactory, StaticServiceProvider.Instance.GetRequiredService<ILogger<UserGroupPresentationFactory>>())
+    {
+    }
+
+    public UserGroupPresentationFactory(
+        IEntityService entityService,
+        IShortStringHelper shortStringHelper,
+        ILanguageService languageService,
+        IPermissionPresentationFactory permissionPresentationFactory,
+        ILogger<UserGroupPresentationFactory> logger)
     {
         _entityService = entityService;
         _shortStringHelper = shortStringHelper;
         _languageService = languageService;
         _permissionPresentationFactory = permissionPresentationFactory;
+        _logger = logger;
     }
 
     /// <inheritdoc />
@@ -43,10 +57,9 @@ public class UserGroupPresentationFactory : IUserGroupPresentationFactory
 
         Attempt<IEnumerable<string>, UserGroupOperationStatus> languageIsoCodesMappingAttempt = await MapLanguageIdsToIsoCodeAsync(userGroup.AllowedLanguages);
 
-        // We've gotten this data from the database, so the mapping should not fail
         if (languageIsoCodesMappingAttempt.Success is false)
         {
-            throw new InvalidOperationException($"Unknown language ID in User Group: {userGroup.Name}");
+            _logger.LogDebug("Unknown language ID in User Group: {0}", userGroup.Name);
         }
 
         return new UserGroupResponseModel
@@ -77,10 +90,9 @@ public class UserGroupPresentationFactory : IUserGroupPresentationFactory
         Guid? mediaStartNodeKey = GetKeyFromId(userGroup.StartMediaId, UmbracoObjectTypes.Media);
         Attempt<IEnumerable<string>, UserGroupOperationStatus> languageIsoCodesMappingAttempt = await MapLanguageIdsToIsoCodeAsync(userGroup.AllowedLanguages);
 
-        // We've gotten this data from the database, so the mapping should not fail
         if (languageIsoCodesMappingAttempt.Success is false)
         {
-            throw new InvalidOperationException($"Unknown language ID in User Group: {userGroup.Name}");
+            _logger.LogDebug("Unknown language ID in User Group: {0}", userGroup.Name);
         }
 
         return new UserGroupResponseModel
@@ -217,9 +229,10 @@ public class UserGroupPresentationFactory : IUserGroupPresentationFactory
             .Select(x => x.IsoCode)
             .ToArray();
 
-        return isoCodes.Length == ids.Count()
-            ? Attempt.SucceedWithStatus<IEnumerable<string>, UserGroupOperationStatus>(UserGroupOperationStatus.Success, isoCodes)
-            : Attempt.FailWithStatus<IEnumerable<string>, UserGroupOperationStatus>(UserGroupOperationStatus.LanguageNotFound, isoCodes);
+        // if a language id does not exist, it simply not returned.
+        // We do this so we don't have to clean up user group data when deleting languages and to make it easier to restore accidentally removed languages
+        return Attempt.SucceedWithStatus<IEnumerable<string>, UserGroupOperationStatus>(
+            UserGroupOperationStatus.Success, isoCodes);
     }
 
     private async Task<Attempt<IEnumerable<int>, UserGroupOperationStatus>> MapLanguageIsoCodesToIdsAsync(IEnumerable<string> isoCodes)