diff --git a/app/templates/bank_import/index.html b/app/templates/bank_import/index.html
index e7cc854..1b4d687 100644
--- a/app/templates/bank_import/index.html
+++ b/app/templates/bank_import/index.html
@@ -314,8 +314,17 @@
     fd.append('file', selectedFile);
     if (colMap) fd.append('col_map', JSON.stringify(colMap));
 
-    fetch('{{ url_for("bank_import.parse") }}', { method: 'POST', body: fd })
-      .then(r => r.json())
+    fetch('{{ url_for("bank_import.parse") }}', {
+        method: 'POST',
+        headers: { 'X-CSRFToken': CSRF },
+        body: fd,
+      })
+      .then(r => {
+        if (!r.ok && !r.headers.get('content-type')?.includes('application/json')) {
+          throw new Error(`Server error ${r.status} — check server logs for details.`);
+        }
+        return r.json();
+      })
       .then(data => {
         setParseLoading(false);
         if (data.error) {