diff --git a/src/BambuStudio.cpp b/src/BambuStudio.cpp
index 3d0b55443..dcfc117c4 100644
--- a/src/BambuStudio.cpp
+++ b/src/BambuStudio.cpp
@@ -2876,8 +2876,10 @@ int CLI::run(int argc, char **argv)
             flush_and_exit(ret);
         }
     }
-    new_extruder_count = m_print_config.option<ConfigOptionFloatsNullable>("nozzle_diameter")->values.size();
-    new_is_multi_extruder = new_extruder_count > 1;
+    if (m_print_config.option<ConfigOptionFloatsNullable>("nozzle_diameter")) {
+        new_extruder_count = m_print_config.option<ConfigOptionFloatsNullable>("nozzle_diameter")->values.size();
+        new_is_multi_extruder = new_extruder_count > 1;
+    }
 
     //set the process settings into print config
     std::vector<std::string>& print_compatible_printers = m_print_config.option<ConfigOptionStrings>("print_compatible_printers", true)->values;
@@ -3264,7 +3266,7 @@ int CLI::run(int argc, char **argv)
                 std::copy(min_flush_volumes.begin(), min_flush_volumes.end(), std::ostream_iterator<int>(volumes_str, ","));
                 BOOST_LOG_TRIVIAL(info) << boost::format("extra_flush_volume: %1%") % volumes_str.str();
                 BOOST_LOG_TRIVIAL(info) << boost::format("filament_is_support: %1%") % filament_is_support->serialize();
-                BOOST_LOG_TRIVIAL(info) << boost::format("flush_volumes_matrix before computing: %1%") % m_print_config.option<ConfigOptionFloats>("flush_volumes_matrix")->serialize();
+                BOOST_LOG_TRIVIAL(info) << boost::format("flush_volumes_matrix before computing: %1%") % m_print_config.option<ConfigOptionFloats>("flush_volumes_matrix", true)->serialize();
             }
 
             std::vector<double> &flush_vol_matrix = m_print_config.option<ConfigOptionFloats>("flush_volumes_matrix", true)->values;