1 files changed, 9 insertions, 3 deletions
diff --git a/launcher/minecraft/mod/tasks/LocalModUpdateTask.cpp b/launcher/minecraft/mod/tasks/LocalModUpdateTask.cpp
index f0ef795d..4b878918 100644
--- a/launcher/minecraft/mod/tasks/LocalModUpdateTask.cpp
+++ b/launcher/minecraft/mod/tasks/LocalModUpdateTask.cpp
@@ -47,12 +47,18 @@ void LocalModUpdateTask::executeTask()
     auto old_metadata = Metadata::get(m_index_dir, m_mod.addonId);
     if (old_metadata.isValid()) {
         emit hasOldMod(old_metadata.name, old_metadata.filename);
+        if (m_mod.slug.isEmpty())
+            m_mod.slug = old_metadata.slug;
     }
 
     auto pw_mod = Metadata::create(m_index_dir, m_mod, m_mod_version);
-    Metadata::update(m_index_dir, pw_mod);
-
-    emitSucceeded();
+    if (pw_mod.isValid()) {
+        Metadata::update(m_index_dir, pw_mod);
+        emitSucceeded();
+    } else {
+        qCritical() << "Tried to update an invalid mod!";
+        emitFailed(tr("Invalid metadata"));
+    }
 }
 
 auto LocalModUpdateTask::abort() -> bool