diff --git a/.github/workflows/build-and-deploy-production.yml b/.github/workflows/build-and-deploy-production.yml
index 38d34a51c2..b1579fb2d1 100644
--- a/.github/workflows/build-and-deploy-production.yml
+++ b/.github/workflows/build-and-deploy-production.yml
@@ -19,10 +19,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Setup .NET Core SDK 6.0
+      - name: Setup .NET Core SDK 8.0
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: 6.0.x
+          dotnet-version: 8.0.x
       - name: Setup node
         uses: actions/setup-node@v4
         with:
diff --git a/.github/workflows/build-and-deploy-uat.yml b/.github/workflows/build-and-deploy-uat.yml
index 9a82da00a9..e06b88c727 100644
--- a/.github/workflows/build-and-deploy-uat.yml
+++ b/.github/workflows/build-and-deploy-uat.yml
@@ -22,10 +22,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Setup .NET Core SDK 6.0
+      - name: Setup .NET Core SDK 8.0
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: 6.0.x
+          dotnet-version: 8.0.x
       - name: Setup node
         uses: actions/setup-node@v4
         with:
diff --git a/.github/workflows/continuous-integration-workflow.yml b/.github/workflows/continuous-integration-workflow.yml
index d0019ac854..3b0ed25380 100644
--- a/.github/workflows/continuous-integration-workflow.yml
+++ b/.github/workflows/continuous-integration-workflow.yml
@@ -12,10 +12,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Setup .NET Core SDK 6.0
+      - name: Setup .NET Core SDK 8.0
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: 6.0.x
+          dotnet-version: 8.0.x
 
       - name: Add TechnologyEnhancedLearning as nuget package source
         run: dotnet nuget add source https://pkgs.dev.azure.com/e-LfH/_packaging/LearningHubFeed/nuget/v3/index.json --name TechnologyEnhancedLearning --username 'kevin.whittaker' --password ${{ secrets.AZURE_DEVOPS_PAT }} --store-password-in-clear-text
diff --git a/DigitalLearningSolutions.Data.Migrations/202410071401_UpdateCandidateAssessmentSupervisorsTabl.cs b/DigitalLearningSolutions.Data.Migrations/202410071401_UpdateCandidateAssessmentSupervisorsTabl.cs
deleted file mode 100644
index de95a04841..0000000000
--- a/DigitalLearningSolutions.Data.Migrations/202410071401_UpdateCandidateAssessmentSupervisorsTabl.cs
+++ /dev/null
@@ -1,21 +0,0 @@
-
-namespace DigitalLearningSolutions.Data.Migrations
-{
-    using FluentMigrator;
-
-    [Migration(202410071401)]
-    public class UpdateCandidateAssessmentSupervisorsTabl : ForwardOnlyMigration
-    {
-        public override void Up()
-        {
-            Execute.Sql($@"UPDATE cas 
-                SET SelfAssessmentSupervisorRoleID = (SELECT ID FROM SelfAssessmentSupervisorRoles 
-                    WHERE SelfAssessmentID = ssr.SelfAssessmentID and AllowDelegateNomination = 1) 
-                FROM CandidateAssessmentSupervisors cas INNER JOIN 
-                    SelfAssessmentSupervisorRoles ssr ON cas.SelfAssessmentSupervisorRoleID = ssr.ID 
-                    AND cas.Removed IS NULL AND ssr.AllowDelegateNomination = 0 INNER JOIN 
-                    SupervisorDelegates sd ON cas.SupervisorDelegateId = sd.ID INNER JOIN 
-                    AdminAccounts aa ON sd.SupervisorAdminID = aa.ID WHERE aa.IsSupervisor = 0 AND aa.IsNominatedSupervisor = 1");
-        }
-    }
-}
diff --git a/DigitalLearningSolutions.Data/DataServices/RegistrationDataService.cs b/DigitalLearningSolutions.Data/DataServices/RegistrationDataService.cs
index d6b229e721..ced09e50f3 100644
--- a/DigitalLearningSolutions.Data/DataServices/RegistrationDataService.cs
+++ b/DigitalLearningSolutions.Data/DataServices/RegistrationDataService.cs
@@ -197,7 +197,7 @@ public int RegisterAdmin(
                 isSupervisor = registrationModel.IsSupervisor,
                 isNominatedSupervisor = registrationModel.IsNominatedSupervisor,
             };
-
+            
             var adminUserId = connection.QuerySingle<int>(
                 @"INSERT INTO AdminAccounts
                     (
@@ -219,7 +219,10 @@ OUTPUT Inserted.ID
                     (
                         @userId,
                         @centreId,
-                        @categoryId,
+                        CASE 
+                        WHEN @categoryID = 0 THEN NULL 
+                        ELSE @categoryID 
+                        END,
                         @isCentreAdmin,
                         @isCentreManager,
                         @active,
diff --git a/DigitalLearningSolutions.Data/DataServices/SelfAssessmentDataService/SelfAssessmentSupervisorDataService.cs b/DigitalLearningSolutions.Data/DataServices/SelfAssessmentDataService/SelfAssessmentSupervisorDataService.cs
index 8ae5e54133..7c3a5d118f 100644
--- a/DigitalLearningSolutions.Data/DataServices/SelfAssessmentDataService/SelfAssessmentSupervisorDataService.cs
+++ b/DigitalLearningSolutions.Data/DataServices/SelfAssessmentDataService/SelfAssessmentSupervisorDataService.cs
@@ -95,7 +95,8 @@ int delegateUserId
                     WHERE (sd.Removed IS NULL) AND (cas.Removed IS NULL) AND (sd.DelegateUserID = @delegateUserId)
                         AND (ca.SelfAssessmentID = @selfAssessmentId) AND (sd.SupervisorAdminID IS NOT NULL)
                         AND (coalesce(sasr.ResultsReview, 1) = 1)
-                        AND au.Active = 1 
+                        AND au.Active = 1
+                        AND (au.CategoryID = 0 OR au.CategoryID IN (select CategoryID from SelfAssessments where ID = @selfAssessmentId))
                     ORDER BY SupervisorName",
                 new { selfAssessmentId, delegateUserId }
             );
diff --git a/DigitalLearningSolutions.Web/Controllers/SupervisorController/Supervisor.cs b/DigitalLearningSolutions.Web/Controllers/SupervisorController/Supervisor.cs
index e051d12737..11d8ab1e7d 100644
--- a/DigitalLearningSolutions.Web/Controllers/SupervisorController/Supervisor.cs
+++ b/DigitalLearningSolutions.Web/Controllers/SupervisorController/Supervisor.cs
@@ -1314,7 +1314,7 @@ public IActionResult ConfirmNominateSupervisor(SupervisorDelegateViewModel super
                     supervisorDelegateDetail.DelegateUserID,
                     (int)User.GetCentreId()
                 );
-                supervisorDelegate.SelfAssessmentCategory = supervisorDelegate.SelfAssessmentCategory == 0 ? adminUser.CategoryId.Value : supervisorDelegate.SelfAssessmentCategory;
+                supervisorDelegate.SelfAssessmentCategory = supervisorDelegate.SelfAssessmentCategory == 0 ? (adminUser.CategoryId.HasValue ? adminUser.CategoryId.Value : 0) : supervisorDelegate.SelfAssessmentCategory;
                 var centreName = adminUser.CentreName;
 
                 var adminRoles = new AdminRoles(false, false, true, false, false, false, false, false);