diff --git a/README.md b/README.md
index 1d4d73e..4601e9c 100644
--- a/README.md
+++ b/README.md
@@ -65,7 +65,7 @@ To set up the demo, run the following command:
 vectory demo
 ```
 
-You can specify the demo dataset with the `dataset_name` argument. See `vectory demo --help` for more information.
+You can specify the demo dataset by adding the name as the next argument. See `vectory demo --help` for more information.
 
 
 <p align="center">
diff --git a/TROUBLESHOOTING.md b/TROUBLESHOOTING.md
index 5d32a40..ccbedb3 100644
--- a/TROUBLESHOOTING.md
+++ b/TROUBLESHOOTING.md
@@ -23,6 +23,41 @@ sqlite3.OperationalError: database is locked
 ```
 Just stop the running instance of Vectory and try again.
 
+
+### Index already exists
+
+If adding an index to the database fails in a way we haven't anticipated, it might happen that the index is loaded in Elasticsearch but not in the database. This can be checked by comparing the indices on both places:
+
+```python
+from vectory.db.models import ElasticSearchIndexModel, Query
+from vectory.es.client import ElasticKNNClient
+
+es = ElasticKNNClient()
+es_indices = es.list_indices()
+
+db_indices = Query(ElasticSearchIndexModel).get()
+```
+
+`es_indices` and `db_indices` should be the same.
+
+If the index is on Elasticsearch but not in the database, delete it from Elasticsearch and try again.
+
+```python
+from vectory.es.client import ElasticKNNClient
+
+es = ElasticKNNClient()
+es.delete_index(INDEX_NAME)
+```
+
+If the index is in the database but not on Elasticsearch, delete it from the database and try again.
+
+```
+from vectory.db.models import ElasticSearchIndexModel, Query
+
+index = Query(ElasticSearchIndexModel).get(name=INDEX_NAME)[0]
+index.delete_instance(recursive=False)
+```
+
 ## Import errors
 
 ### No module `pkg_resources`