diff --git a/aider/help.py b/aider/help.py
index c7c8f7f48..c3104d9d7 100755
--- a/aider/help.py
+++ b/aider/help.py
@@ -58,6 +58,9 @@ def fname_to_url(filepath):
     return docid
 
 
+import json
+import shutil
+
 def get_index():
     from llama_index.core import (
         Document,
@@ -69,35 +72,46 @@ def get_index():
 
     dname = Path.home() / ".aider" / "caches" / ("help." + __version__)
 
+    index = None
+
     if dname.exists():
+        try:
+            storage_context = StorageContext.from_defaults(
+                persist_dir=dname,
+            )
+            index = load_index_from_storage(storage_context)
+        except (OSError, json.JSONDecodeError):
+            shutil.rmtree(dname)
+            pass
         storage_context = StorageContext.from_defaults(
             persist_dir=dname,
         )
         index = load_index_from_storage(storage_context)
     else:
+    if index is None:
         parser = MarkdownNodeParser()
 
-        nodes = []
-        for fname in get_package_files():
-            fname = Path(fname)
-            if any(fname.match(pat) for pat in exclude_website_pats):
-                continue
+        nodes = [] 
+        for fname in get_package_files(): 
+            fname = Path(fname) 
+            if any(fname.match(pat) for pat in exclude_website_pats): 
+                continue 
 
-            doc = Document(
-                text=importlib_resources.files("aider.website")
-                .joinpath(fname)
-                .read_text(encoding="utf-8"),
-                metadata=dict(
-                    filename=fname.name,
-                    extension=fname.suffix,
-                    url=fname_to_url(str(fname)),
-                ),
-            )
-            nodes += parser.get_nodes_from_documents([doc])
+            doc = Document( 
+                text=importlib_resources.files("aider.website") 
+                .joinpath(fname) 
+                .read_text(encoding="utf-8"), 
+                metadata=dict( 
+                    filename=fname.name, 
+                    extension=fname.suffix, 
+                    url=fname_to_url(str(fname)), 
+                ), 
+            ) 
+            nodes += parser.get_nodes_from_documents([doc]) 
 
-        index = VectorStoreIndex(nodes, show_progress=True)
-        dname.parent.mkdir(parents=True, exist_ok=True)
-        index.storage_context.persist(dname)
+        index = VectorStoreIndex(nodes, show_progress=True) 
+        dname.parent.mkdir(parents=True, exist_ok=True) 
+        index.storage_context.persist(dname) 
 
     return index