diff --git a/src/libslic3r/Print.cpp b/src/libslic3r/Print.cpp
index ad3cafcb1..d159f75df 100644
--- a/src/libslic3r/Print.cpp
+++ b/src/libslic3r/Print.cpp
@@ -1334,7 +1334,10 @@ void Print::process(bool use_cache)
     name_tbb_thread_pool_threads_set_locale();
 
     //compute the PrintObject with the same geometries
-    BOOST_LOG_TRIVIAL(info) << __FUNCTION__ << boost::format(": this=%1%, enter, use_cache=%2%")%this%use_cache;
+    BOOST_LOG_TRIVIAL(info) << __FUNCTION__ << boost::format(": this=%1%, enter, use_cache=%2%, object size=%3%")%this%use_cache%m_objects.size();
+    if (m_objects.empty())
+        return;
+
     for (PrintObject *obj : m_objects)
         obj->clear_shared_object();
 
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index c8777af6f..56abcbff2 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -5635,7 +5635,8 @@ void Plater::priv::on_process_completed(SlicingProcessCompletedEvent &evt)
     }
 
     //BBS: set the current plater's slice result to valid
-    this->background_process.get_current_plate()->update_slice_result_valid_state(evt.success());
+    if (!this->background_process.empty())
+        this->background_process.get_current_plate()->update_slice_result_valid_state(evt.success());
 
     //BBS: update the action button according to the current plate's status
     bool ready_to_slice = !this->partplate_list.get_curr_plate()->is_slice_result_valid();