diff --git a/ortools/sat/cp_model_presolve.cc b/ortools/sat/cp_model_presolve.cc
index d13fc71b19..35e0a2a9dc 100644
--- a/ortools/sat/cp_model_presolve.cc
+++ b/ortools/sat/cp_model_presolve.cc
@@ -13707,6 +13707,7 @@ namespace {
 void UpdateHintInProto(PresolveContext* context) {
   CpModelProto* proto = context->working_model;
   if (!proto->has_solution_hint()) return;
+  if (context->ModelIsUnsat()) return;
 
   // Extract the new hint information from the context.
   auto* mutable_hint = proto->mutable_solution_hint();
diff --git a/ortools/sat/scheduling_cuts.cc b/ortools/sat/scheduling_cuts.cc
index ff61542625..cee4ec0ab5 100644
--- a/ortools/sat/scheduling_cuts.cc
+++ b/ortools/sat/scheduling_cuts.cc
@@ -718,6 +718,7 @@ CutGenerator CreateCumulativeTimeTableCutGenerator(
     TopNCuts top_n_cuts(5);
     std::vector<TimeTableEvent> events;
     const auto& lp_values = manager->LpValues();
+    if (lp_values.empty()) return true;  // No linear relaxation.
     const double capacity_lp = capacity.LpValue(lp_values);
 
     // Iterate through the intervals. If start_max < end_min, the demand