diff --git a/src/redux/slices/submit.ts b/src/redux/slices/submit.ts
index b70efe8..21522b1 100644
--- a/src/redux/slices/submit.ts
+++ b/src/redux/slices/submit.ts
@@ -8,7 +8,7 @@ export interface Submit {
     language: string;
     languageVersion: string;
     sourceCode: string;
-    contestId: number | null;
+    contestId?: number;
 }
 
 export interface Solution {
@@ -30,8 +30,8 @@ export interface MissionSubmit {
     id: number;
     userId: number;
     solution: Solution;
-    contestId: number | null;
-    contestName: string | null;
+    contestId?: number;
+    contestName?: string;
     sourceType: string;
 }
 
@@ -40,7 +40,7 @@ interface SubmitState {
     submitsById: Record<number, MissionSubmit[]>; // ✅ добавлено
     currentSubmit?: Submit;
     status: 'idle' | 'loading' | 'successful' | 'failed';
-    error: string | null;
+    error?: string;
 }
 
 // Начальное состояние
@@ -49,7 +49,7 @@ const initialState: SubmitState = {
     submitsById: {}, // ✅ инициализация
     currentSubmit: undefined,
     status: 'idle',
-    error: null,
+    error: undefined,
 };
 
 // AsyncThunk: Отправка решения
@@ -123,7 +123,7 @@ const submitSlice = createSlice({
         clearCurrentSubmit: (state) => {
             state.currentSubmit = undefined;
             state.status = 'idle';
-            state.error = null;
+            state.error = undefined;
         },
         clearSubmitsByMission: (state, action: PayloadAction<number>) => {
             delete state.submitsById[action.payload];
@@ -133,7 +133,7 @@ const submitSlice = createSlice({
         // Отправка решения
         builder.addCase(submitMission.pending, (state) => {
             state.status = 'loading';
-            state.error = null;
+            state.error = undefined;
         });
         builder.addCase(
             submitMission.fulfilled,
@@ -153,7 +153,7 @@ const submitSlice = createSlice({
         // Получить все свои отправки
         builder.addCase(fetchMySubmits.pending, (state) => {
             state.status = 'loading';
-            state.error = null;
+            state.error = undefined;
         });
         builder.addCase(
             fetchMySubmits.fulfilled,
@@ -173,7 +173,7 @@ const submitSlice = createSlice({
         // Получить отправку по ID
         builder.addCase(fetchSubmitById.pending, (state) => {
             state.status = 'loading';
-            state.error = null;
+            state.error = undefined;
         });
         builder.addCase(
             fetchSubmitById.fulfilled,
@@ -193,7 +193,7 @@ const submitSlice = createSlice({
         // ✅ Получить отправки по миссии
         builder.addCase(fetchMySubmitsByMission.pending, (state) => {
             state.status = 'loading';
-            state.error = null;
+            state.error = undefined;
         });
         builder.addCase(
             fetchMySubmitsByMission.fulfilled,