diff --git a/back/src/Kyoo.Core/Controllers/Repositories/SeasonRepository.cs b/back/src/Kyoo.Core/Controllers/Repositories/SeasonRepository.cs
index 8dc193c5..3d20216e 100644
--- a/back/src/Kyoo.Core/Controllers/Repositories/SeasonRepository.cs
+++ b/back/src/Kyoo.Core/Controllers/Repositories/SeasonRepository.cs
@@ -107,7 +107,7 @@ namespace Kyoo.Core.Controllers
 		{
 			await base.Create(obj);
 			_database.Entry(obj).State = EntityState.Added;
-			await _database.SaveChangesAsync(() => Get(obj.Slug));
+			await _database.SaveChangesAsync(() => Get(obj.ShowID, obj.SeasonNumber));
 			return obj;
 		}
 
diff --git a/scanner/providers/implementations/themoviedatabase.py b/scanner/providers/implementations/themoviedatabase.py
index 1d04f6ec..5e3dc426 100644
--- a/scanner/providers/implementations/themoviedatabase.py
+++ b/scanner/providers/implementations/themoviedatabase.py
@@ -4,6 +4,8 @@ from aiohttp import ClientSession
 from datetime import datetime
 from typing import Awaitable, Callable, Dict, Optional, Any, TypeVar
 
+from providers.utils import ProviderError
+
 from ..provider import Provider
 from ..types.movie import Movie, MovieTranslation, Status as MovieStatus
 from ..types.season import Season, SeasonTranslation
@@ -97,9 +99,12 @@ class TheMovieDatabase(Provider):
 	async def identify_movie(
 		self, name: str, year: Optional[int], *, language: list[str]
 	) -> Movie:
-		search = (await self.get("search/movie", params={"query": name, "year": year}))[
-			"results"
-		][0]
+		search_results = (
+			await self.get("search/movie", params={"query": name, "year": year})
+		)["results"]
+		if len(search_results) == 0:
+			raise ProviderError(f"No result for a movie named: {name}")
+		search = search_results[0]
 		movie_id = search["id"]
 		if search["original_language"] not in language:
 			language.append(search["original_language"])
@@ -118,9 +123,9 @@ class TheMovieDatabase(Provider):
 			ret = Movie(
 				original_language=movie["original_language"],
 				aliases=[x["title"] for x in movie["alternative_titles"]["titles"]],
-				release_date=datetime.strptime(
-					movie["release_date"], "%Y-%m-%d"
-				).date(),
+				release_date=datetime.strptime(movie["release_date"], "%Y-%m-%d").date()
+				if movie["release_date"]
+				else None,
 				status=MovieStatus.FINISHED
 				if movie["status"] == "Released"
 				else MovieStatus.PLANNED,
@@ -184,8 +189,12 @@ class TheMovieDatabase(Provider):
 			ret = Show(
 				original_language=show["original_language"],
 				aliases=[x["title"] for x in show["alternative_titles"]["results"]],
-				start_air=datetime.strptime(show["first_air_date"], "%Y-%m-%d").date(),
-				end_air=datetime.strptime(show["last_air_date"], "%Y-%m-%d").date(),
+				start_air=datetime.strptime(show["first_air_date"], "%Y-%m-%d").date()
+				if show["first_air_date"]
+				else None,
+				end_air=datetime.strptime(show["last_air_date"], "%Y-%m-%d").date()
+				if show["last_air_date"]
+				else None,
 				status=ShowStatus.FINISHED
 				if show["status"] == "Released"
 				else ShowStatus.AIRING
@@ -258,7 +267,9 @@ class TheMovieDatabase(Provider):
 	) -> Season:
 		return Season(
 			season_number=season["season_number"],
-			start_air=datetime.strptime(season["air_date"], "%Y-%m-%d").date(),
+			start_air=datetime.strptime(season["air_date"], "%Y-%m-%d").date()
+			if season["air_date"]
+			else None,
 			end_air=None,
 			external_ids={
 				self.name: MetadataID(
@@ -289,14 +300,19 @@ class TheMovieDatabase(Provider):
 		*,
 		language: list[str],
 	) -> Episode:
-		search = (await self.get("search/tv", params={"query": name}))["results"][0]
+		search_results = (await self.get("search/tv", params={"query": name}))[
+			"results"
+		]
+		if len(search_results) == 0:
+			raise ProviderError(f"No result for a tv show named: {name}")
+		search = search_results[0]
 		show_id = search["id"]
 		if search["original_language"] not in language:
 			language.append(search["original_language"])
 
 		# TODO: Handle absolute episodes
 		if not season or not episode_nbr:
-			raise NotImplementedError(
+			raise ProviderError(
 				"Absolute order episodes not implemented for the movie database"
 			)
 
@@ -323,7 +339,9 @@ class TheMovieDatabase(Provider):
 				episode_number=episode["episode_number"],
 				# TODO: absolute numbers
 				absolute_number=None,
-				release_date=datetime.strptime(episode["air_date"], "%Y-%m-%d").date(),
+				release_date=datetime.strptime(episode["air_date"], "%Y-%m-%d").date()
+				if episode["air_date"]
+				else None,
 				thumbnail=f"https://image.tmdb.org/t/p/original{episode['poster_path']}"
 				if "poster_path" in episode
 				else None,
diff --git a/scanner/providers/types/season.py b/scanner/providers/types/season.py
index fde20130..ca7094b4 100644
--- a/scanner/providers/types/season.py
+++ b/scanner/providers/types/season.py
@@ -9,18 +9,18 @@ from .metadataid import MetadataID
 
 @dataclass
 class SeasonTranslation:
-	name: Optional[str]
-	overview: Optional[str]
-	posters: list[str]
-	thumbnails: list[str]
+	name: Optional[str] = None
+	overview: Optional[str] = None
+	posters: list[str] = field(default_factory=list)
+	thumbnails: list[str] = field(default_factory=list)
 
 
 @dataclass
 class Season:
 	season_number: int
-	start_air: Optional[date | int]
-	end_air: Optional[date | int]
-	external_ids: dict[str, MetadataID]
+	start_air: Optional[date | int] = None
+	end_air: Optional[date | int] = None
+	external_ids: dict[str, MetadataID] = field(default_factory=dict)
 
 	show_id: Optional[str] = None
 	translations: dict[str, SeasonTranslation] = field(default_factory=dict)
diff --git a/scanner/providers/utils.py b/scanner/providers/utils.py
index c0e6d8a2..27b38212 100644
--- a/scanner/providers/utils.py
+++ b/scanner/providers/utils.py
@@ -7,3 +7,7 @@ def format_date(date: date | int | None) -> str | None:
 	if isinstance(date, int):
 		return f"{date}-01-01"
 	return date.isoformat()
+
+class ProviderError(RuntimeError):
+	def __init__(self, *args: object) -> None:
+		super().__init__(*args)
diff --git a/scanner/scanner/scanner.py b/scanner/scanner/scanner.py
index 22b2df45..60142a88 100644
--- a/scanner/scanner/scanner.py
+++ b/scanner/scanner/scanner.py
@@ -8,7 +8,8 @@ from pathlib import Path
 from guessit import guessit
 from providers.provider import Provider
 from providers.types.episode import Episode, PartialShow
-from providers.types.season import Season
+from providers.types.season import Season, SeasonTranslation
+from providers.utils import ProviderError
 
 
 def log_errors(f):
@@ -16,12 +17,64 @@ def log_errors(f):
 	async def internal(*args, **kwargs):
 		try:
 			await f(*args, **kwargs)
+		except ProviderError as e:
+			logging.error(str(e))
 		except Exception as e:
 			logging.exception("Unhandled error", exc_info=e)
 
 	return internal
 
 
+cache = {}
+
+
+def provider_cache(*args):
+	ic = cache
+	for arg in args:
+		if arg not in ic:
+			ic[arg] = {}
+		ic = ic[arg]
+
+	def wrapper(f):
+		@wraps(f)
+		async def internal(*args, **kwargs):
+			nonlocal ic
+			for arg in args:
+				if arg not in ic:
+					ic[arg] = {}
+				ic = ic[arg]
+
+			if "event" in ic:
+				await ic["event"].wait()
+				if not ic["ret"]:
+					raise ProviderError("Cache miss. Another error should exist")
+				return ic["ret"]
+			ic["event"] = asyncio.Event()
+			try:
+				ret = await f(*args, **kwargs)
+				ic["ret"] = ret
+			except:
+				ic["event"].set()
+				raise
+			ic["event"].set()
+			return ret
+		return internal
+	return wrapper
+
+
+def set_in_cache(key: list[str | int]):
+	ic = cache
+	for arg in key:
+		if arg not in ic:
+			ic[arg] = {}
+		ic = ic[arg]
+	evt = asyncio.Event()
+	evt.set()
+	ic["event"] = evt
+
+
+
+
 class Scanner:
 	def __init__(
 		self, client: ClientSession, *, languages: list[str], api_key: str
@@ -30,7 +83,7 @@ class Scanner:
 		self._api_key = api_key
 		self._url = os.environ.get("KYOO_URL", "http://back:5000")
 		self.provider = Provider.get_all(client)[0]
-		self.cache = {"shows": {}}
+		self.cache = {"shows": {}, "seasons": {}}
 		self.languages = languages
 
 	async def scan(self, path: str):
@@ -50,7 +103,6 @@ class Scanner:
 				return True
 		return False
 
-
 	@log_errors
 	async def identify(self, path: Path):
 		if await self.is_registered(path):
@@ -58,7 +110,6 @@ class Scanner:
 		raw = guessit(path, "--episode-prefer-number")
 		logging.info("Identied %s: %s", path, raw)
 
-		# TODO: check if episode/movie already exists in kyoo and skip if it does.
 		# TODO: Add collections support
 		if raw["type"] == "movie":
 			movie = await self.provider.identify_movie(
@@ -78,47 +129,49 @@ class Scanner:
 			episode.path = str(path)
 			logging.debug("Got episode: %s", episode)
 			episode.show_id = await self.create_or_get_show(episode)
-			# TODO: Do the same things for seasons and wait for them to be created on the api (else the episode creation will fail)
+
+			if episode.season_number is not None:
+				await self.register_seasons(
+					show_id=episode.show_id,
+					season_number=episode.season_number,
+				)
 			await self.post("episodes", data=episode.to_kyoo())
 		else:
 			logging.warn("Unknown video file type: %s", raw["type"])
 
 	async def create_or_get_show(self, episode: Episode) -> str:
-		provider_id = episode.show.external_ids[self.provider.name].id
-		if provider_id in self.cache["shows"]:
-			ret = self.cache["shows"][provider_id]
-			await ret["event"].wait()
-			if not ret["id"]:
-				raise RuntimeError("Provider failed to create the show")
-			return ret["id"]
-
-		self.cache["shows"][provider_id] = {"id": None, "event": asyncio.Event()}
-
-		# TODO: Check if a show with the same metadata id exists already on kyoo.
-
-		show = (
-			await self.provider.identify_show(episode.show, language=self.languages)
-			if isinstance(episode.show, PartialShow)
-			else episode.show
-		)
-		logging.debug("Got show: %s", episode)
-		try:
+		@provider_cache("shows")
+		async def create_show(_: str):
+			# TODO: Check if a show with the same metadata id exists already on kyoo.
+			show = (
+				await self.provider.identify_show(episode.show, language=self.languages)
+				if isinstance(episode.show, PartialShow)
+				else episode.show
+			)
+			logging.debug("Got show: %s", episode)
 			ret = await self.post("show", data=show.to_kyoo())
-		except:
-			# Allow tasks waiting for this show to bail out.
-			self.cache["shows"][provider_id]["event"].set()
-			raise
-		self.cache["shows"][provider_id]["id"] = ret
-		self.cache["shows"][provider_id]["event"].set()
+			try:
+				for season in show.seasons:
+					season.show_id = ret
+					await self.post("seasons", data=season.to_kyoo())
+					set_in_cache(key=["seasons", ret, season.season_number])
+			except Exception as e:
+				logging.exception("Unhandled error create a season", exc_info=e)
+			return ret
 
-		# TODO: Better handling of seasons registrations (maybe a lock also)
-		await self.register_seasons(ret, show.seasons)
-		return ret
+		# The parameter is only used as a key for the cache.
+		provider_id = episode.show.external_ids[self.provider.name].id
+		return await create_show(provider_id)
 
-	async def register_seasons(self, show_id: str, seasons: list[Season]):
-		for season in seasons:
-			season.show_id = show_id
-			await self.post("seasons", data=season.to_kyoo())
+	@provider_cache("seasons")
+	async def register_seasons(self, show_id: str, season_number: int):
+		# TODO: fetch season here. this will be useful when a new season of a show is aired after the show has been created on kyoo.
+		season = Season(
+			season_number=season_number,
+			show_id=show_id,
+			translations={lng: SeasonTranslation() for lng in self.languages},
+		)
+		await self.post("seasons", data=season.to_kyoo())
 
 	async def post(self, path: str, *, data: object) -> str:
 		logging.debug(