diff --git a/srcs/requirements/nestjs/api_back/src/chat/chat.service.ts b/srcs/requirements/nestjs/api_back/src/chat/chat.service.ts
index 5de334f5..10ebc6ba 100644
--- a/srcs/requirements/nestjs/api_back/src/chat/chat.service.ts
+++ b/srcs/requirements/nestjs/api_back/src/chat/chat.service.ts
@@ -347,12 +347,18 @@ export class ChatService {
 		let relation = await this.findOneRelationshipByUsername(to_block_username, username);
 		if (relation)
 		{
-			let blocked_friendship = await this.friendshipService.blockFriendship(relation.id, user);
+			await this.friendshipService.blockFriendship(relation.id, user);
 		}
 		else
 		{
 			const newFriendshipDto = {"receiverUsername": to_block_username, "status": FriendshipStatus.BLOCKED};
-			await this.friendshipService.create(newFriendshipDto, user);
+			if (newFriendshipDto)
+				await this.friendshipService.create(newFriendshipDto, user);
+			else
+			{
+				printCaller(`throw error: error: true, code: 'BLOCK_USER_FAILED', message: 'we couldn't block the user because it was not found'`);
+				throw new HttpException({ error: true, code: 'BLOCK_USER_FAILED', message: `we couldn't block the user because it was not found` }, HttpStatus.UNAUTHORIZED);
+			}
 		}
 
 		printCaller("-- out ");
@@ -363,8 +369,16 @@ export class ChatService {
 		printCaller("-- in ");
 
 		let user = await this.getUserByName(username);
-		let relation = await this.findOneRelationshipByUsername(to_unblock_username, username);
-		await this.friendshipService.removeFriendship(relation.id, user);
+		let relation: SendableFriendship;
+		if (user)
+			relation = await this.findOneRelationshipByUsername(to_unblock_username, username);
+		if (relation)
+			await this.friendshipService.removeFriendship(relation.id, user);
+		else
+		{
+			printCaller(`throw error: error: true, code: 'REMOVE_USER_FAILED', message: 'we couldn't unblock the user because it was not found'`);
+			throw new HttpException({ error: true, code: 'REMOVE_USER_FAILED', message: `we couldn't unblock the user because it was not found` }, HttpStatus.UNAUTHORIZED);
+		}
 
 		printCaller("-- out ");
 	}
@@ -373,9 +387,11 @@ export class ChatService {
 	{
 		printCaller("-- in ");
 
+		let users: string[] = [];
+		let friends_users: SendableFriendship[];
 		let user = await this.getUserByName(username);
-		let friends_users = await this.friendshipService.findAllBlockedFriends(user.id);
-		let users: string[];
+		if (user)
+			friends_users = await this.friendshipService.findAllBlockedFriends(user.id);
 		if (friends_users)
 			users = friends_users.map(user => user.receiverUsername);