diff --git a/meilisearch-types/src/error.rs b/meilisearch-types/src/error.rs
index 886a0fe30..ff9b06d85 100644
--- a/meilisearch-types/src/error.rs
+++ b/meilisearch-types/src/error.rs
@@ -218,6 +218,7 @@ MissingDocumentFilter                 , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentFilter                 , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentGeoField               , InvalidRequest       , BAD_REQUEST ;
 InvalidVectorDimensions               , InvalidRequest       , BAD_REQUEST ;
+InvalidVectorsType                    , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentId                     , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentLimit                  , InvalidRequest       , BAD_REQUEST ;
 InvalidDocumentOffset                 , InvalidRequest       , BAD_REQUEST ;
@@ -337,6 +338,7 @@ impl ErrorCode for milli::Error {
                     UserError::CriterionError(_) => Code::InvalidSettingsRankingRules,
                     UserError::InvalidGeoField { .. } => Code::InvalidDocumentGeoField,
                     UserError::InvalidVectorDimensions { .. } => Code::InvalidVectorDimensions,
+                    UserError::InvalidVectorsType { .. } => Code::InvalidVectorsType,
                     UserError::SortError(_) => Code::InvalidSearchSort,
                     UserError::InvalidMinTypoWordLenSetting(_, _) => {
                         Code::InvalidSettingsTypoTolerance
diff --git a/milli/src/error.rs b/milli/src/error.rs
index a12334f90..3df599b61 100644
--- a/milli/src/error.rs
+++ b/milli/src/error.rs
@@ -112,6 +112,8 @@ only composed of alphanumeric characters (a-z A-Z 0-9), hyphens (-) and undersco
     InvalidGeoField(#[from] GeoError),
     #[error("Invalid vector dimensions: expected: `{}`, found: `{}`.", .expected, .found)]
     InvalidVectorDimensions { expected: usize, found: usize },
+    #[error("The `_vectors` field in the document with the id: `{document_id}` is not an array. Was expecting an array of floats or an array of arrays of floats but instead got `{value}`.")]
+    InvalidVectorsType { document_id: Value, value: Value },
     #[error("{0}")]
     InvalidFilter(String),
     #[error("Invalid type for filter subexpression: expected: {}, found: {1}.", .0.join(", "))]
diff --git a/milli/src/update/index_documents/extract/extract_vector_points.rs b/milli/src/update/index_documents/extract/extract_vector_points.rs
index c2a08b320..e78dbc080 100644
--- a/milli/src/update/index_documents/extract/extract_vector_points.rs
+++ b/milli/src/update/index_documents/extract/extract_vector_points.rs
@@ -3,9 +3,10 @@ use std::fs::File;
 use std::io;
 
 use bytemuck::cast_slice;
-use serde_json::from_slice;
+use serde_json::{from_slice, Value};
 
 use super::helpers::{create_writer, writer_into_reader, GrenadParameters};
+use crate::error::UserError;
 use crate::{FieldId, InternalError, Result, VectorOrArrayOfVectors};
 
 /// Extracts the embedding vector contained in each document under the `_vectors` field.
@@ -15,6 +16,7 @@ use crate::{FieldId, InternalError, Result, VectorOrArrayOfVectors};
 pub fn extract_vector_points<R: io::Read + io::Seek>(
     obkv_documents: grenad::Reader<R>,
     indexer: GrenadParameters,
+    primary_key_id: FieldId,
     vectors_fid: FieldId,
 ) -> Result<grenad::Reader<File>> {
     let mut writer = create_writer(
@@ -27,14 +29,23 @@ pub fn extract_vector_points<R: io::Read + io::Seek>(
     while let Some((docid_bytes, value)) = cursor.move_on_next()? {
         let obkv = obkv::KvReader::new(value);
 
+        // since we only needs the primary key when we throw an error we create this getter to
+        // lazily get it when needed
+        let document_id = || -> Value {
+            let document_id = obkv.get(primary_key_id).unwrap();
+            serde_json::from_slice(document_id).unwrap()
+        };
+
         // first we retrieve the _vectors field
         if let Some(vectors) = obkv.get(vectors_fid) {
             // extract the vectors
-            // TODO return a user error before unwrapping
-            let vectors = from_slice(vectors)
-                .map_err(InternalError::SerdeJson)
-                .map(VectorOrArrayOfVectors::into_array_of_vectors)
-                .unwrap();
+            let vectors = match from_slice(vectors) {
+                Ok(vectors) => VectorOrArrayOfVectors::into_array_of_vectors(vectors),
+                Err(_) => return Err(UserError::InvalidVectorsType {
+                    document_id: document_id(),
+                    value: from_slice(vectors).map_err(InternalError::SerdeJson)?,
+                }.into()),
+            };
 
             for (i, vector) in vectors.into_iter().enumerate() {
                 match u16::try_from(i) {
diff --git a/milli/src/update/index_documents/extract/mod.rs b/milli/src/update/index_documents/extract/mod.rs
index 14f08b106..6259c7272 100644
--- a/milli/src/update/index_documents/extract/mod.rs
+++ b/milli/src/update/index_documents/extract/mod.rs
@@ -316,7 +316,12 @@ fn send_and_extract_flattened_documents_data(
         let documents_chunk_cloned = flattened_documents_chunk.clone();
         let lmdb_writer_sx_cloned = lmdb_writer_sx.clone();
         rayon::spawn(move || {
-            let result = extract_vector_points(documents_chunk_cloned, indexer, vectors_field_id);
+            let result = extract_vector_points(
+                documents_chunk_cloned,
+                indexer,
+                primary_key_id,
+                vectors_field_id,
+            );
             let _ = match result {
                 Ok(vector_points) => {
                     lmdb_writer_sx_cloned.send(Ok(TypedChunk::VectorPoints(vector_points)))