diff --git a/public/index.html b/public/index.html
index f7da844..393dc02 100644
--- a/public/index.html
+++ b/public/index.html
@@ -1086,10 +1086,11 @@
     async function confirmSubmit() {
       if (!pendingFile) return;
 
+      const fileToSubmit = pendingFile; // save ref before closeModal nulls it
       closeModal();
 
       const formData = new FormData();
-      formData.append('prproj', pendingFile);
+      formData.append('prproj', fileToSubmit);
 
       const progressEl = document.getElementById('upload-progress');
       const statusEl = document.getElementById('upload-status');