diff --git a/paskia/db/operations.py b/paskia/db/operations.py
index 72444a7..b476058 100644
--- a/paskia/db/operations.py
+++ b/paskia/db/operations.py
@@ -79,16 +79,18 @@ class DB:
     async def load(self, db_path: str | None = None) -> None:
         """Load data from JSONL change log.
 
-        If file doesn't exist, keeps the initialized empty structure and
+        If file doesn't exist or is empty, keeps the initialized empty structure and
         sets _previous_builtins to {} for creating a new database.
         """
         if db_path is not None:
             self.db_path = Path(db_path)
         try:
             data_dict = await load_jsonl(self.db_path)
-            self._data = _json_decoder.decode(_json_encoder.encode(data_dict))
-            # Track the JSONL file state directly - this is what we diff against
-            self._previous_builtins = data_dict
+            if data_dict:  # Only decode if we have data
+                self._data = _json_decoder.decode(_json_encoder.encode(data_dict))
+                # Track the JSONL file state directly - this is what we diff against
+                self._previous_builtins = data_dict
+            # If data_dict is empty, keep initialized _data and _previous_builtins = {}
         except ValueError:
             if self.db_path.exists():
                 raise  # File exists but failed to load - re-raise
diff --git a/paskia/db/structs.py b/paskia/db/structs.py
index 6ccd0ce..630731a 100644
--- a/paskia/db/structs.py
+++ b/paskia/db/structs.py
@@ -100,7 +100,7 @@ class _OrgData(msgspec.Struct):
 class _RoleData(msgspec.Struct):
     org: UUID
     display_name: str
-    permissions: dict[UUID, bool]  # permission_uuid -> True
+    permissions: dict[UUID, bool] = {}  # permission_uuid -> True
 
 
 class _UserData(msgspec.Struct):
diff --git a/paskia/fastapi/admin.py b/paskia/fastapi/admin.py
index b74e3b1..4e23814 100644
--- a/paskia/fastapi/admin.py
+++ b/paskia/fastapi/admin.py
@@ -273,15 +273,23 @@ async def admin_create_role(
     perms = payload.get("permissions") or []
     org = db.get_organization(str(org_uuid))
     grantable = set(org.permissions or [])
+    
+    # Normalize permission IDs to UUIDs
+    permission_uuids = []
     for pid in perms:
-        db.get_permission(pid)
-        if pid not in grantable:
+        perm = db.get_permission(pid)
+        if not perm:
+            raise ValueError(f"Permission {pid} not found")
+        perm_uuid_str = str(perm.uuid)
+        if perm_uuid_str not in grantable:
             raise ValueError(f"Permission not grantable by org: {pid}")
+        permission_uuids.append(perm_uuid_str)
+    
     role = RoleDC(
         uuid=role_uuid,
         org_uuid=org_uuid,
         display_name=display_name,
-        permissions=perms,
+        permissions=permission_uuids,
     )
     db.create_role(role, ctx=ctx)
     return {"uuid": str(role_uuid)}
@@ -506,10 +514,13 @@ async def admin_update_user_role(
     if ctx.user.uuid == user_uuid:
         new_role_obj = next((r for r in roles if r.display_name == new_role), None)
         if new_role_obj:  # pragma: no branch - always true, role validated above
-            has_admin_access = (
-                "auth:admin" in new_role_obj.permissions
-                or "auth:org:admin" in new_role_obj.permissions
-            )
+            # Check if any permission in the new role is an admin permission
+            has_admin_access = False
+            for perm_uuid in new_role_obj.permissions:
+                perm = db.get_permission(perm_uuid)
+                if perm and perm.scope in ["auth:admin", "auth:org:admin"]:
+                    has_admin_access = True
+                    break
             if not has_admin_access:
                 raise ValueError(
                     "Cannot change your own role to one without admin permissions"
@@ -917,9 +928,9 @@ async def admin_list_permissions(request: Request, auth=AUTH_COOKIE):
     if is_global_admin(ctx):
         return [_perm_to_dict(p) for p in perms]
 
-    # Org admins only see permissions their org can grant
+    # Org admins only see permissions their org can grant (by UUID)
     grantable = set(ctx.org.permissions or [])
-    filtered_perms = [p for p in perms if p.scope in grantable]
+    filtered_perms = [p for p in perms if str(p.uuid) in grantable]
     return [_perm_to_dict(p) for p in filtered_perms]
 
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 745221e..0af7d11 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -87,7 +87,7 @@ async def test_org(test_db: DB, admin_permission: Permission) -> Org:
     org = Org(
         uuid=uuid7.create(),
         display_name="Test Organization",
-        permissions=["auth:admin"],  # Org can grant this permission
+        permissions=[str(admin_permission.uuid)],  # Org can grant this permission
     )
     create_organization(org)
     return org
@@ -131,7 +131,7 @@ async def test_role(
         uuid=uuid7.create(),
         org_uuid=test_org.uuid,
         display_name="Test Admin Role",
-        permissions=["auth:admin", "auth:org:admin"],
+        permissions=[str(admin_permission.uuid), str(org_admin_permission.uuid)],
     )
     create_role(role)
     return role
diff --git a/tests/test_admin.py b/tests/test_admin.py
index bb4611b..f7ee8ad 100644
--- a/tests/test_admin.py
+++ b/tests/test_admin.py
@@ -61,7 +61,7 @@ async def second_org_role(
         uuid=uuid7.create(),
         org_uuid=second_org.uuid,
         display_name="Second Org Admin Role",
-        permissions=["auth:admin"],
+        permissions=[str(admin_permission.uuid)],
     )
     create_role(role)
     return role
@@ -120,13 +120,13 @@ async def second_org_session_token(
 
 
 @pytest_asyncio.fixture(scope="function")
-async def org_admin_role(test_db: DB, test_org: Org, org_admin_permission) -> Role:
+async def org_admin_role(test_db: DB, test_org: Org, org_admin_permission: Permission) -> Role:
     """Create a role with org admin permission only (no global admin)."""
     role = Role(
         uuid=uuid7.create(),
         org_uuid=test_org.uuid,
         display_name="Org Admin Role",
-        permissions=["auth:org:admin"],
+        permissions=[str(org_admin_permission.uuid)],
     )
     create_role(role)
     return role
@@ -666,7 +666,7 @@ class TestAdminRoles:
     ):
         """Admin should be able to add grantable permissions to role."""
         response = await client.post(
-            f"/auth/api/admin/orgs/{test_org.uuid}/roles/{user_role.uuid}/permissions/{grantable_permission.scope}",
+            f"/auth/api/admin/orgs/{test_org.uuid}/roles/{user_role.uuid}/permissions/{grantable_permission.uuid}",
             headers={**auth_headers(session_token), "Host": "localhost:4401"},
         )
         assert response.status_code == 200
@@ -691,7 +691,7 @@ class TestAdminRoles:
         create_permission(perm)
 
         response = await client.post(
-            f"/auth/api/admin/orgs/{test_org.uuid}/roles/{user_role.uuid}/permissions/test:not:grantable:update",
+            f"/auth/api/admin/orgs/{test_org.uuid}/roles/{user_role.uuid}/permissions/{perm.uuid}",
             headers={**auth_headers(session_token), "Host": "localhost:4401"},
         )
         assert response.status_code == 400
@@ -700,20 +700,26 @@ class TestAdminRoles:
 
     @pytest.mark.asyncio
     async def test_update_own_role_cannot_remove_admin(
-        self, client: httpx.AsyncClient, session_token: str, test_org, test_role
+        self,
+        client: httpx.AsyncClient,
+        session_token: str,
+        test_org,
+        test_role,
+        admin_permission,
+        org_admin_permission,
     ):
         """Admin cannot remove their own admin permissions."""
         # test_role has both auth:admin and auth:org:admin
         # Remove auth:admin first (should succeed since org:admin remains)
         response = await client.delete(
-            f"/auth/api/admin/orgs/{test_org.uuid}/roles/{test_role.uuid}/permissions/auth:admin",
+            f"/auth/api/admin/orgs/{test_org.uuid}/roles/{test_role.uuid}/permissions/{admin_permission.uuid}",
             headers={**auth_headers(session_token), "Host": "localhost:4401"},
         )
         assert response.status_code == 200
 
         # Now try to remove auth:org:admin (should fail - would leave no admin access)
         response = await client.delete(
-            f"/auth/api/admin/orgs/{test_org.uuid}/roles/{test_role.uuid}/permissions/auth:org:admin",
+            f"/auth/api/admin/orgs/{test_org.uuid}/roles/{test_role.uuid}/permissions/{org_admin_permission.uuid}",
             headers={**auth_headers(session_token), "Host": "localhost:4401"},
         )
         assert response.status_code == 400
@@ -1264,14 +1270,14 @@ class TestAdminSessions:
     async def test_delete_session_invalid_id(
         self, client: httpx.AsyncClient, session_token: str, test_org, test_user
     ):
-        """Deleting session with invalid ID format should fail."""
+        """Deleting session with invalid/non-existent ID should fail."""
         response = await client.delete(
             f"/auth/api/admin/orgs/{test_org.uuid}/users/{test_user.uuid}/sessions/invalid!!id",
             headers={**auth_headers(session_token), "Host": "localhost:4401"},
         )
-        assert response.status_code == 400
+        assert response.status_code == 404
         data = response.json()
-        assert "Invalid session identifier" in data["detail"]
+        assert "Session not found" in data["detail"]
 
     @pytest.mark.asyncio
     async def test_delete_session_not_found(
diff --git a/tests/test_user.py b/tests/test_user.py
index 8c2c1af..7350f12 100644
--- a/tests/test_user.py
+++ b/tests/test_user.py
@@ -117,7 +117,7 @@ class TestUserSessionManagement:
             "/auth/api/user/session/invalid-session-id",
             headers={**auth_headers(session_token), "Host": "localhost:4401"},
         )
-        assert response.status_code == 400
+        assert response.status_code == 404  # Not found (no format validation)
 
     @pytest.mark.asyncio
     async def test_delete_nonexistent_session_returns_404(