diff --git a/src/TaxBaik.Portal.Client/_Imports.razor b/src/TaxBaik.Portal.Client/_Imports.razor
index ee04635..27e9c7e 100644
--- a/src/TaxBaik.Portal.Client/_Imports.razor
+++ b/src/TaxBaik.Portal.Client/_Imports.razor
@@ -9,7 +9,4 @@
 @using Microsoft.JSInterop
 @using MudBlazor
 @using TaxBaik.PortalClient
-@using TaxBaik.WasmClient.Components.Admin
-@using TaxBaik.WasmClient.Components.Admin.Layout
-@using TaxBaik.WasmClient.Components.Admin.Shared
 @using static Microsoft.AspNetCore.Components.Web.RenderMode
diff --git a/src/TaxBaik.Web/Endpoints/CommonCode/AllEndpoints.cs b/src/TaxBaik.Web/Endpoints/CommonCode/AllEndpoints.cs
index 4c28d90..4d0fb47 100644
--- a/src/TaxBaik.Web/Endpoints/CommonCode/AllEndpoints.cs
+++ b/src/TaxBaik.Web/Endpoints/CommonCode/AllEndpoints.cs
@@ -54,7 +54,7 @@ public class GetAllActiveEndpoint : Endpoint<EmptyRequest, CommonCodeResponse>
             var codes = await _service.GetAllActiveAsync();
             await SendAsync(new CommonCodeResponse { Data = codes.Cast<object>().ToList() }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
             ThrowError("공통코드 조회 실패", statusCode: 500);
         }
@@ -77,10 +77,12 @@ public class GetByGroupEndpoint : Endpoint<EmptyRequest, CommonCodeResponse>
         var group = Route<string>("group");
         try
         {
+            if (string.IsNullOrWhiteSpace(group))
+                ThrowError("그룹 코드가 필요합니다.", statusCode: 400);
             var codes = await _service.GetByGroupAsync(group);
             await SendAsync(new CommonCodeResponse { Data = codes.Cast<object>().ToList() }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
             ThrowError("그룹별 공통코드 조회 실패", statusCode: 500);
         }
@@ -105,7 +107,7 @@ public class GetGroupsEndpoint : Endpoint<EmptyRequest, GroupResponse>
             var groups = await _service.GetAllGroupsAsync();
             await SendAsync(new GroupResponse { Data = groups.ToList() }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
             ThrowError("공통코드 그룹 조회 실패", statusCode: 500);
         }
@@ -129,14 +131,16 @@ public class GetByGroupAndValueEndpoint : Endpoint<EmptyRequest, CommonCodeSingl
         var value = Route<string>("value");
         try
         {
+            if (string.IsNullOrWhiteSpace(group) || string.IsNullOrWhiteSpace(value))
+                ThrowError("그룹 코드와 값이 필요합니다.", statusCode: 400);
             var code = await _service.GetAsync(group, value);
             if (code == null)
                 ThrowError("공통코드를 찾을 수 없습니다.", statusCode: 404);
             await SendAsync(new CommonCodeSingleResponse { Data = code }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message, statusCode: 500);
+            ThrowError("공통코드 조회 실패", statusCode: 500);
         }
     }
 }
@@ -177,9 +181,9 @@ public class UpsertEndpoint : Endpoint<UpsertCommonCodeRequest, UpsertCommonCode
             await _service.UpsertAsync(code);
             await SendAsync(new UpsertCommonCodeResponse { Data = code }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message);
+            ThrowError("공통코드 저장 실패");
         }
     }
 }
@@ -201,12 +205,14 @@ public class DeleteEndpoint : Endpoint<EmptyRequest, EmptyResponse>
         var value = Route<string>("value");
         try
         {
+            if (string.IsNullOrWhiteSpace(group) || string.IsNullOrWhiteSpace(value))
+                ThrowError("그룹 코드와 값이 필요합니다.", statusCode: 400);
             await _service.DeleteAsync(group, value);
             await SendNoContentAsync(ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message);
+            ThrowError("공통코드 삭제 실패");
         }
     }
 }
diff --git a/src/TaxBaik.Web/Endpoints/Company/AllEndpoints.cs b/src/TaxBaik.Web/Endpoints/Company/AllEndpoints.cs
index 749e4cb..b9aa3b1 100644
--- a/src/TaxBaik.Web/Endpoints/Company/AllEndpoints.cs
+++ b/src/TaxBaik.Web/Endpoints/Company/AllEndpoints.cs
@@ -82,7 +82,7 @@ public class GetByIdEndpoint : Endpoint<EmptyRequest, CompanyResponse>
                 ThrowError("회사를 찾을 수 없습니다.", statusCode: 404);
             await SendAsync(new CompanyResponse { Data = company }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
             ThrowError("회사 조회 실패", statusCode: 500);
         }
@@ -105,12 +105,14 @@ public class GetByCodeEndpoint : Endpoint<EmptyRequest, CompanyResponse>
         var code = Route<string>("code");
         try
         {
+            if (string.IsNullOrWhiteSpace(code))
+                ThrowError("회사 코드가 필요합니다.", statusCode: 400);
             var company = await _service.GetByCodeAsync(code);
             if (company == null)
                 ThrowError("회사를 찾을 수 없습니다.", statusCode: 404);
             await SendAsync(new CompanyResponse { Data = company }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
             ThrowError("회사 조회 실패", statusCode: 500);
         }
@@ -141,7 +143,7 @@ public class GetPagedEndpoint : Endpoint<GetPagedQuery, CompanyListResponse>
                 PageSize = request.PageSize
             }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
             ThrowError("회사 목록 조회 실패", statusCode: 500);
         }
@@ -172,7 +174,7 @@ public class CreateEndpoint : Endpoint<CreateCompanyRequest, CompanyCreateRespon
         {
             ThrowError(ex.Message);
         }
-        catch (Exception ex)
+        catch
         {
             ThrowError("회사 등록 실패", statusCode: 500);
         }
@@ -203,7 +205,7 @@ public class UpdateEndpoint : Endpoint<UpdateCompanyRequest, CompanyUpdateRespon
         {
             ThrowError(ex.Message);
         }
-        catch (Exception ex)
+        catch
         {
             ThrowError("회사 수정 실패", statusCode: 500);
         }
@@ -233,7 +235,7 @@ public class DeleteEndpoint : Endpoint<EmptyRequest, CompanyDeleteResponse>
         {
             ThrowError(ex.Message);
         }
-        catch (Exception ex)
+        catch
         {
             ThrowError("회사 삭제 실패", statusCode: 500);
         }
diff --git a/src/TaxBaik.Web/Endpoints/ConsultingActivity/AllEndpoints.cs b/src/TaxBaik.Web/Endpoints/ConsultingActivity/AllEndpoints.cs
index bde397f..2bc52ac 100644
--- a/src/TaxBaik.Web/Endpoints/ConsultingActivity/AllEndpoints.cs
+++ b/src/TaxBaik.Web/Endpoints/ConsultingActivity/AllEndpoints.cs
@@ -16,6 +16,8 @@ public class CreateEp : Endpoint<CreatReq, IdResp>
     public override void Configure() { Post("/api/consultingactivity"); Policies("Bearer"); }
     public override async Task HandleAsync(CreatReq r, CancellationToken ct)
     {
+        if (string.IsNullOrWhiteSpace(r.ActivityType) || string.IsNullOrWhiteSpace(r.Notes))
+            ThrowError("활동 유형과 메모가 필요합니다.", statusCode: 400);
         var id = await _s.CreateAsync(r.ClientId, r.ActivityType, r.ActivityDate, r.Notes);
         await SendAsync(new IdResp { Id = id }, 201, cancellation: ct);
     }
diff --git a/src/TaxBaik.Web/Endpoints/Contract/AllEndpoints.cs b/src/TaxBaik.Web/Endpoints/Contract/AllEndpoints.cs
index e9d5a6a..797e99e 100644
--- a/src/TaxBaik.Web/Endpoints/Contract/AllEndpoints.cs
+++ b/src/TaxBaik.Web/Endpoints/Contract/AllEndpoints.cs
@@ -16,6 +16,8 @@ public class CreateEp : Endpoint<CreateRequest, IdResp>
     public override void Configure() { Post("/api/contract"); Policies("Bearer"); }
     public override async Task HandleAsync(CreateRequest r, CancellationToken ct)
     {
+        if (string.IsNullOrWhiteSpace(r.ContractNumber) || string.IsNullOrWhiteSpace(r.ServiceType))
+            ThrowError("계약번호와 서비스 유형이 필요합니다.", statusCode: 400);
         var id = await _svc.CreateAsync(r.ClientId, r.ContractNumber, r.ServiceType, r.StartDate, r.MonthlyFee, r.TotalAmount);
         await SendAsync(new IdResp { Id = id }, 201, cancellation: ct);
     }
diff --git a/src/TaxBaik.Web/Endpoints/TaxFiling/AllEndpoints.cs b/src/TaxBaik.Web/Endpoints/TaxFiling/AllEndpoints.cs
index 851f11c..d52515e 100644
--- a/src/TaxBaik.Web/Endpoints/TaxFiling/AllEndpoints.cs
+++ b/src/TaxBaik.Web/Endpoints/TaxFiling/AllEndpoints.cs
@@ -62,9 +62,9 @@ public class GetUpcomingEndpoint : Endpoint<GetUpcomingQuery, TaxFilingListRespo
             var filings = await _service.GetUpcomingAsync(request.DaysAhead);
             await SendAsync(new TaxFilingListResponse { Data = filings.Cast<object>().ToList() }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message, statusCode: 500);
+            ThrowError("예정 신고 조회 실패", statusCode: 500);
         }
     }
 }
@@ -88,9 +88,9 @@ public class GetByClientIdEndpoint : Endpoint<EmptyRequest, TaxFilingListRespons
             var filings = await _service.GetByClientIdAsync(clientId);
             await SendAsync(new TaxFilingListResponse { Data = filings.Cast<object>().ToList() }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message, statusCode: 500);
+            ThrowError("고객별 신고 조회 실패", statusCode: 500);
         }
     }
 }
@@ -116,9 +116,9 @@ public class GetByIdEndpoint : Endpoint<EmptyRequest, object>
                 ThrowError("신고 일정을 찾을 수 없습니다.", statusCode: 404);
             await SendAsync(filing, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message, statusCode: 500);
+            ThrowError("신고 상세 조회 실패", statusCode: 500);
         }
     }
 }
@@ -141,18 +141,18 @@ public class CreateEndpoint : Endpoint<CreateTaxFilingRequest, TaxFilingResponse
             var filing = new TaxFilingEntity
             {
                 ClientId = request.ClientId,
-                FilingType = request.FilingType,
+                FilingType = request.FilingType ?? string.Empty,
                 DueDate = request.DueDate,
-                Status = request.Status,
+                Status = request.Status ?? "pending",
                 Memo = request.Memo
             };
             var filingId = await _service.CreateAsync(filing);
             var result = await _service.GetByIdAsync(filingId);
             await SendAsync(new TaxFilingResponse { Id = filingId }, 201, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message);
+            ThrowError("신고 생성 실패");
         }
     }
 }
@@ -176,9 +176,9 @@ public class UpdateEndpoint : Endpoint<UpdateTaxFilingRequest, TaxFilingUpdateRe
             var filing = new TaxFilingEntity
             {
                 Id = id,
-                FilingType = request.FilingType,
+                FilingType = request.FilingType ?? string.Empty,
                 DueDate = request.DueDate ?? DateTime.Now,
-                Status = request.Status,
+                Status = request.Status ?? "pending",
                 Memo = request.Memo
             };
             await _service.UpdateAsync(filing);
@@ -187,9 +187,9 @@ public class UpdateEndpoint : Endpoint<UpdateTaxFilingRequest, TaxFilingUpdateRe
                 ThrowError("신고 일정을 찾을 수 없습니다.", statusCode: 404);
             await SendAsync(new TaxFilingUpdateResponse { Message = "신고 일정이 수정되었습니다." }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message);
+            ThrowError("신고 수정 실패");
         }
     }
 }
@@ -213,9 +213,9 @@ public class DeleteEndpoint : Endpoint<EmptyRequest, EmptyResponse>
             await _service.DeleteAsync(id);
             await SendNoContentAsync(ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message);
+            ThrowError("신고 삭제 실패");
         }
     }
 }
diff --git a/src/TaxBaik.Web/Endpoints/TaxFilingSchedule/AllEndpoints.cs b/src/TaxBaik.Web/Endpoints/TaxFilingSchedule/AllEndpoints.cs
index 9c3c916..eb49eeb 100644
--- a/src/TaxBaik.Web/Endpoints/TaxFilingSchedule/AllEndpoints.cs
+++ b/src/TaxBaik.Web/Endpoints/TaxFilingSchedule/AllEndpoints.cs
@@ -31,6 +31,8 @@ public class CreateEndpoint : Endpoint<CreateRequest, IdResponse>
 
     public override async Task HandleAsync(CreateRequest req, CancellationToken ct)
     {
+        if (string.IsNullOrWhiteSpace(req.FilingType))
+            ThrowError("신고 유형이 필요합니다.", statusCode: 400);
         var id = await _svc.CreateAsync(req.ClientId, req.FilingType, req.DueDate, req.FilingYear, req.AssignedToId);
         await SendAsync(new IdResponse { Id = id }, 201, cancellation: ct);
     }
diff --git a/src/TaxBaik.Web/Endpoints/TaxProfile/AllEndpoints.cs b/src/TaxBaik.Web/Endpoints/TaxProfile/AllEndpoints.cs
index f517eb9..8682273 100644
--- a/src/TaxBaik.Web/Endpoints/TaxProfile/AllEndpoints.cs
+++ b/src/TaxBaik.Web/Endpoints/TaxProfile/AllEndpoints.cs
@@ -86,9 +86,9 @@ public class GetAllEndpoint : Endpoint<EmptyRequest, TaxProfileListResponse>
             var profiles = await _service.GetAllAsync();
             await SendAsync(new TaxProfileListResponse { Data = profiles.Cast<object>().ToList() }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message, statusCode: 500);
+            ThrowError("세무 프로필 조회 실패", statusCode: 500);
         }
     }
 }
@@ -114,9 +114,9 @@ public class GetByClientIdEndpoint : Endpoint<EmptyRequest, object>
                 ThrowError("세무 프로필을 찾을 수 없습니다.", statusCode: 404);
             await SendAsync(profile, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message, statusCode: 500);
+            ThrowError("세무 프로필 조회 실패", statusCode: 500);
         }
     }
 }
@@ -139,9 +139,9 @@ public class GetHighRiskEndpoint : Endpoint<EmptyRequest, TaxProfileListResponse
             var profiles = await _service.GetHighRiskProfilesAsync();
             await SendAsync(new TaxProfileListResponse { Data = profiles.Cast<object>().ToList() }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message, statusCode: 500);
+            ThrowError("고위험 세무 프로필 조회 실패", statusCode: 500);
         }
     }
 }
@@ -164,9 +164,9 @@ public class GetUpcomingFilingsEndpoint : Endpoint<DaysAheadQuery, object>
             var profiles = await _service.GetUpcomingFilingDuesAsync(request.DaysAhead);
             await SendAsync(new { data = profiles, daysAhead = request.DaysAhead }, 200, cancellation: ct);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message, statusCode: 500);
+            ThrowError("예정 신고 조회 실패", statusCode: 500);
         }
     }
 }
@@ -187,6 +187,8 @@ public class UpdateEndpoint : Endpoint<UpdateTaxProfileRequest, TaxProfileUpdate
         var id = Route<int>("id");
         try
         {
+            if (request.TaxRiskLevel is null)
+                request.TaxRiskLevel = "normal";
             await _service.UpdateAsync(id, request.BusinessType, request.AccountingMethod,
                 request.NextFilingDueDate, request.TaxRiskLevel);
             await SendAsync(new TaxProfileUpdateResponse { Message = "세무 프로필이 수정되었습니다." }, 200, cancellation: ct);
@@ -195,9 +197,9 @@ public class UpdateEndpoint : Endpoint<UpdateTaxProfileRequest, TaxProfileUpdate
         {
             ThrowError(ex.Message);
         }
-        catch (Exception ex)
+        catch
         {
-            ThrowError(ex.Message, statusCode: 500);
+            ThrowError("세무 프로필 수정 실패", statusCode: 500);
         }
     }
 }
diff --git a/src/TaxBaik.Web/Program.cs b/src/TaxBaik.Web/Program.cs
index 38ad826..49e44d8 100644
--- a/src/TaxBaik.Web/Program.cs
+++ b/src/TaxBaik.Web/Program.cs
@@ -395,7 +395,6 @@ app.MapStaticAssets();
 // Blazor WebAssembly Admin Client
 app.MapRazorComponents<TaxBaik.WasmClient.Components.Admin.App>()
    .AddInteractiveWebAssemblyRenderMode()
-   .AddAdditionalAssemblies(typeof(TaxBaik.WasmClient._Imports).Assembly)
    .AllowAnonymous();
 
 // SPA 라우팅 폴백 (가장 마지막에!)