diff --git a/public/site/templates/project.json.php b/public/site/templates/project.json.php
index cb17600..4ad5068 100644
--- a/public/site/templates/project.json.php
+++ b/public/site/templates/project.json.php
@@ -91,7 +91,7 @@ function processDTLProposals($page) {
         }
 
         if ($DTLProposal) {            
-            if ($proposalFile->cover()->isNotEmpty()) {                
+            if (isset($proposalFile) && $proposalFile->cover()->isNotEmpty()) {                
                 $DTLProposal["thumb"] = $proposalFile->cover()->toFile()->thumb([
                     "width" => 200,
                     "format" => "webp"