commit - 516a00f1223763e16b5d1397c25041fc40a166b1
commit + 450bef9e6cbe05e2842b97cf709b594f45128352
blob - 372d2fb60f8cc950409c849890eb63a02cbad61e
blob + e7385de709f3c06c7c6064a3fd44b1996a2c5d92
--- src/procedures.c
+++ src/procedures.c
@@ -579,6 +579,8 @@ uint8_t makeBlockChange (short x, uint8_t y, short z, 
     // which naturally appends the chest to the end if a gap isn't found.
     int last_real_entry = first_gap - 1;
     for (int i = first_gap; i <= block_changes_count + 15; i ++) {
+      if (i >= MAX_BLOCK_CHANGES) break; // No more space, trigger failBlockChange
+
       if (block_changes[i].block != 0xFF) {
         last_real_entry = i;
         continue;