diff --git a/lib/galaxy/files/sources/_pyfilesystem2.py b/lib/galaxy/files/sources/_pyfilesystem2.py
index e604a6c8f75f..efdb5ac79ca8 100644
--- a/lib/galaxy/files/sources/_pyfilesystem2.py
+++ b/lib/galaxy/files/sources/_pyfilesystem2.py
@@ -16,7 +16,10 @@
 from fs.base import FS
 from typing_extensions import Unpack
 
-from galaxy.exceptions import MessageException
+from galaxy.exceptions import (
+    AuthenticationRequired,
+    MessageException,
+)
 from . import (
     BaseFilesSource,
     FilesSourceOptions,
@@ -58,7 +61,7 @@ def _list(self, path="/", recursive=False, user_context=None, opts: Optional[Fil
                     to_dict = functools.partial(self._resource_info_to_dict, path)
                     return list(map(to_dict, res))
         except fs.errors.PermissionDenied as e:
-            raise MessageException(
+            raise AuthenticationRequired(
                 f"Permission Denied. Reason: {e}. Please check your credentials in your preferences for {self.label}."
             )
         except fs.errors.FSError as e:
diff --git a/lib/galaxy/files/sources/_rdm.py b/lib/galaxy/files/sources/_rdm.py
index 7d9a97d2fb5f..14f7e9e1daa0 100644
--- a/lib/galaxy/files/sources/_rdm.py
+++ b/lib/galaxy/files/sources/_rdm.py
@@ -7,7 +7,7 @@
 
 from typing_extensions import Unpack
 
-from galaxy.exceptions import MessageException
+from galaxy.exceptions import AuthenticationRequired
 from galaxy.files import ProvidesUserFileSourcesUserContext
 from galaxy.files.sources import (
     BaseFilesSource,
@@ -199,7 +199,7 @@ def get_authorization_token(self, user_context: OptionalUserContext) -> str:
             effective_props = self._serialization_props(user_context)
             token = effective_props.get("token")
         if not token:
-            raise MessageException(
+            raise AuthenticationRequired(
                 f"Please provide a personal access token in your user's preferences for '{self.label}'"
             )
         return token
diff --git a/lib/galaxy/files/sources/dropbox.py b/lib/galaxy/files/sources/dropbox.py
index 865338da2bbd..70c994e3e2e4 100644
--- a/lib/galaxy/files/sources/dropbox.py
+++ b/lib/galaxy/files/sources/dropbox.py
@@ -8,7 +8,10 @@
     Union,
 )
 
-from galaxy.exceptions import MessageException
+from galaxy.exceptions import (
+    AuthenticationRequired,
+    MessageException,
+)
 from . import (
     FilesSourceOptions,
     FilesSourceProperties,
@@ -35,7 +38,7 @@ def _open_fs(self, user_context=None, opts: Optional[FilesSourceOptions] = None)
             # This plugin might raise dropbox.dropbox_client.BadInputException
             # which is not a subclass of fs.errors.FSError
             if "OAuth2" in str(e):
-                raise MessageException(
+                raise AuthenticationRequired(
                     f"Permission Denied. Reason: {e}. Please check your credentials in your preferences for {self.label}."
                 )
             raise MessageException(f"Error connecting to Dropbox. Reason: {e}")