All the library (included natives) process are test finished.

core_lib/common/exception.py

@@ -2,14 +2,54 @@ from pathlib import Path
 
 
 class LauncherException(Exception):
-    def __init__(self, message):
-        self.message = message
+    user_message = "Launcher error occurred."
 
-    def __str__(self):
-        return self.message
+    def __init__(self, message=None, *, user_message=None):
+        super().__init__(message or user_message or self.user_message)
+        if user_message is not None:
+            self.user_message = user_message
 
 class HashMismatchException(Exception):
     def __init__(self, hash_name, got_hash, expected_hash, filepath: str | Path):
         if type(filepath) == Path: filepath = Path(filepath).absolute().as_posix()
         self.message = "File {} hash mismatch. Expected hash {}. Got hash {} ({})".format(filepath, got_hash,
                                                                                           expected_hash, hash_name)
+        super().__init__(self.message)
+
+class UnsupportedPlatformException(LauncherException):
+    user_message = "Current platform or architecture is not supported."
+
+class VersionNotSelectedException(LauncherException):
+    user_message = "Select a version before continuing."
+
+class VersionManifestFetchException(LauncherException):
+    user_message = "Unable to fetch version manifest."
+
+class VersionManifestSaveException(LauncherException):
+    user_message = "Unable to save version manifest."
+
+class NoVersionFoundException(LauncherException):
+    user_message = "No version found. (This should never happen)"
+
+class NoSpecifiedVersionKeyException(LauncherException):
+    user_message = "Specified version or type not found."
+
+class VersionDataKeyNotFoundException(LauncherException):
+    user_message = "Specified version data section (key) not found."
+
+class VersionManifestException(LauncherException):
+    user_message = "Unable to load version manifest."
+
+class DependencyException(LauncherException):
+    user_message = "Unable to find dependency."
+
+class NativeResolveException(LauncherException):
+    user_message = "Unable to resolve native libraries."
+
+
+class DownloadException(LauncherException):
+    user_message = "Some files failed to download."
+
+class ExtractException(LauncherException):
+    user_message = "Unable to extract native libraries."
+