diff --git a/memhub/apps/core/src/one_memory/api.py b/memhub/apps/core/src/one_memory/api.py
index 5a4a495..23d3a2c 100644
--- a/memhub/apps/core/src/one_memory/api.py
+++ b/memhub/apps/core/src/one_memory/api.py
@@ -130,6 +130,7 @@ from one_memory.hy_sdk_types import (
 from one_memory.imports.access import (
     AuthorizedSourceRoot,
     SourceAccessError,
+    resolved_source_root,
     root_identity_matches,
     source_root_identity,
 )
@@ -172,6 +173,7 @@ from one_memory.imports.sources.common import SourceInstallState
 from one_memory.imports.sources.hermes import (
     HERMES_ROOT_IS_PROFILES_CONTAINER,
     hermes_root_conflict,
+    hermes_root_is_profiles_container,
 )
 from one_memory.imports.sources.registry import (
     RootCandidateKind,
@@ -3217,17 +3219,26 @@ def create_app(
         """
         if source_id not in MULTI_USER_SOURCES:
             return
+        if hermes_root_is_profiles_container(root):
+            raise HTTPException(status_code=422, detail=HERMES_ROOT_IS_PROFILES_CONTAINER)
 
-        def others() -> list[Path]:
-            return [
+        def conflict_with_others() -> str | None:
+            try:
+                mine = resolved_source_root(root)
+            except SourceAccessError:
+                # Unreadable or missing: the grant that follows refuses it
+                # with its own code.
+                return None
+            others = [
                 Path(path)
                 for receipt, path in _grant_store(app).grants()
                 if receipt.source_id == source_id
                 and receipt.user_id != user_id
                 and receipt.revoked_at is None
             ]
+            return hermes_root_conflict(mine, others)
 
-        conflict = hermes_root_conflict(root, await asyncio.to_thread(others))
+        conflict = await asyncio.to_thread(conflict_with_others)
         if conflict is not None:
             raise HTTPException(
                 status_code=422 if conflict == HERMES_ROOT_IS_PROFILES_CONTAINER else 409,
diff --git a/memhub/apps/core/src/one_memory/imports/access.py b/memhub/apps/core/src/one_memory/imports/access.py
index f028b47..6cea3f0 100644
--- a/memhub/apps/core/src/one_memory/imports/access.py
+++ b/memhub/apps/core/src/one_memory/imports/access.py
@@ -436,6 +436,11 @@ def root_identity_matches(root: Path, expected: str) -> bool:
     return _root_identity_matches_details(resolved, details, expected)
 
 
+def resolved_source_root(root: Path) -> Path:
+    """The real directory a root names (symlinks followed), as a grant records it."""
+    return _root_details(root)[0]
+
+
 def _check_root_identity(root: Path, expected: str | None) -> None:
     if expected is not None and not root_identity_matches(root, expected):
         raise SourceAccessError(SourceAccessErrorCode.SOURCE_IDENTITY_CHANGED)
diff --git a/memhub/apps/core/src/one_memory/imports/sources/hermes.py b/memhub/apps/core/src/one_memory/imports/sources/hermes.py
index 24e5e50..8458140 100644
--- a/memhub/apps/core/src/one_memory/imports/sources/hermes.py
+++ b/memhub/apps/core/src/one_memory/imports/sources/hermes.py
@@ -268,20 +268,21 @@ def _is_hermes_target(relative_path: str) -> bool:
     return path.name == "state.db" or (path.suffix == ".jsonl" and "sessions" in path.parts)
 
 
-def hermes_root_conflict(root: Path, other_users_roots: Iterable[Path]) -> str | None:
-    """Why `root` may not be granted beside other users' Hermes roots, or None.
+def hermes_root_is_profiles_container(root: Path) -> bool:
+    """`profiles` itself holds everyone's profiles; it is never one person's history."""
+    return root.name == HERMES_PROFILES_DIRECTORY
 
-    Paths are compared resolved (symlinks followed). `profiles` itself is the
-    container of everyone's profiles, never one person's history. Two roots
-    that are equal or nest would read the same files for two users, except
-    when one is exactly the other's `profiles/<name>`: the scan above never
-    enters `profiles/`, so the two stay apart (`local` on `~/.hermes`, a user
-    on `~/.hermes/profiles/<name>`).
+
+def hermes_root_conflict(mine: Path, other_users_roots: Iterable[Path]) -> str | None:
+    """Why the resolved root `mine` may not be granted beside other users' Hermes roots.
+
+    Paths are compared resolved (symlinks followed; the other users' roots are
+    resolved here). Two roots that are equal or nest would read the same files
+    for two users, except when one is exactly the other's `profiles/<name>`:
+    the scan above never enters `profiles/`, so the two stay apart (`local` on
+    `~/.hermes`, a user on `~/.hermes/profiles/<name>`). None when it may.
     """
-    if root.name == HERMES_PROFILES_DIRECTORY:
-        return HERMES_ROOT_IS_PROFILES_CONTAINER
-    mine = _real(root)
-    if mine.name == HERMES_PROFILES_DIRECTORY:
+    if hermes_root_is_profiles_container(mine):
         return HERMES_ROOT_IS_PROFILES_CONTAINER
     for other in other_users_roots:
         theirs = _real(other)