diff --git a/core/app/datasource/src/main/java/io/openk9/datasource/web/DataIndexResource.java b/core/app/datasource/src/main/java/io/openk9/datasource/web/DataIndexResource.java
index b05c106fa..acf1d156d 100644
--- a/core/app/datasource/src/main/java/io/openk9/datasource/web/DataIndexResource.java
+++ b/core/app/datasource/src/main/java/io/openk9/datasource/web/DataIndexResource.java
@@ -28,6 +28,7 @@
 import io.smallrye.mutiny.Uni;
 import io.smallrye.mutiny.unchecked.Unchecked;
 import io.vertx.core.json.Json;
+import io.vertx.core.json.JsonObject;
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
@@ -41,6 +42,7 @@
 import org.opensearch.cluster.metadata.Template;
 import org.opensearch.common.compress.CompressedXContent;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.indices.InvalidIndexTemplateException;
 
 import java.time.OffsetDateTime;
 import java.util.LinkedHashSet;
@@ -52,9 +54,11 @@
 import javax.persistence.criteria.CriteriaBuilder;
 import javax.persistence.criteria.CriteriaQuery;
 import javax.persistence.criteria.Root;
+import javax.ws.rs.BadRequestException;
 import javax.ws.rs.POST;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
+import javax.ws.rs.core.Response;
 
 @CircuitBreaker
 @Path("/v1/data-index")
@@ -255,6 +259,16 @@ public Uni<DataIndex> createDataIndexFromDocTypes(
 								sink.complete(null);
 							}
 							catch (Exception e) {
+								if (e instanceof InvalidIndexTemplateException ose) {
+									sink.fail(new BadRequestException(Response
+										.status(400)
+										.entity(JsonObject.of(
+											"details",
+											ose.getDetailedMessage()
+										))
+										.build()));
+									return;
+								}
 								sink.fail(e);
 							}