diff --git a/CHANGES.md b/CHANGES.md
index 341f24f9c..44065aee4 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,7 @@
 #### [unreleased]
 * remove `git_updater_plugin_updates` and `git_updater_theme_updates` options, see [#1119](https://github.com/afragen/git-updater/issues/1119)
 * add `gu_plugin_name()` to return plugin name, slug or slug-didhash
+* include the reason why an API data response is incorrect
 
 #### 12.20.2 / 2025-12-08
 * harden REST API data for versions if relesase_assets and tags are empty -- this can happen if too many tags are created that aren't semver format
diff --git a/src/Git_Updater/REST/REST_API.php b/src/Git_Updater/REST/REST_API.php
index d880f068d..4e1bf2114 100644
--- a/src/Git_Updater/REST/REST_API.php
+++ b/src/Git_Updater/REST/REST_API.php
@@ -457,8 +457,15 @@ public function get_api_data( WP_REST_Request $request ) {
 		add_filter( 'gu_disable_wpcron', '__return_false' );
 		$repo_data = Singleton::get_instance( 'Fragen\Git_Updater\Base', $this )->get_remote_repo_meta( $gu_repos[ $slug ] );
 
-		if ( ! is_object( $repo_data ) || '0.0.0' === $repo_data->remote_version ) {
-			return (object) [ 'error' => 'API data response is incorrect.' ];
+		$api_data_incorrect_error  = (object) [ 'error' => 'API data response is incorrect.' ];
+		if ( ! is_object( $repo_data ) ) {
+			$repo_data_type                   = gettype( $repo_data );
+			$api_data_incorrect_error->error .= " Object expected, {$repo_data_type} returned.";
+			return $api_data_incorrect_error;
+		}
+		if ( '0.0.0' === $repo_data->remote_version ) {
+			$api_data_incorrect_error->error .= ' The remote version is "0.0.0".';
+			return $api_data_incorrect_error;
 		}
 
 		$last_updated = ! empty( $repo_data->created_at ) ? reset( $repo_data->created_at ) : $repo_data->last_updated;