diff --git a/Source/Game/Runtime.cpp b/Source/Game/Runtime.cpp
index 44183f78..af2d7813 100644
--- a/Source/Game/Runtime.cpp
+++ b/Source/Game/Runtime.cpp
@@ -61,6 +61,11 @@ const char* currentVersion =
 #ifdef PERIMETER_DEBUG
 " Debug"
 #endif
+#ifdef PERIMETER_ARCH_64
+" 64 bits"
+#else
+" 32 bits"
+#endif
 ;
 
 uint16_t currentVersionNumbers[] = {0, 0, 0};
diff --git a/Source/Render/D3D/D3DRender.cpp b/Source/Render/D3D/D3DRender.cpp
index 6e1c56ce..1decde70 100644
--- a/Source/Render/D3D/D3DRender.cpp
+++ b/Source/Render/D3D/D3DRender.cpp
@@ -1234,7 +1234,11 @@ void cD3DRender::DeleteDynamicBuffers() {
 }
 
 const uint32_t D3D_LOCK_FLAGS_STATIC = D3DLOCK_NOSYSLOCK | D3DLOCK_NO_DIRTY_UPDATE;
+#ifndef PERIMETER_ARCH_64
 const uint32_t D3D_LOCK_FLAGS_DYNAMIC = D3D_LOCK_FLAGS_STATIC | D3DLOCK_DISCARD;
+#else
+const uint32_t D3D_LOCK_FLAGS_DYNAMIC = D3D_LOCK_FLAGS_STATIC;
+#endif
 
 void cD3DRender::UpdateD3DVertexBuffer(VertexBuffer* vb, size_t len) {
     xassert(!vb->burned);
@@ -1267,8 +1271,15 @@ void cD3DRender::UpdateD3DVertexBuffer(VertexBuffer* vb, size_t len) {
     void* lock_ptr = nullptr;
     uint32_t flags = vb->dynamic ? D3D_LOCK_FLAGS_DYNAMIC : D3D_LOCK_FLAGS_STATIC;
     RDCALL(vb->d3d->Lock(0, len, &lock_ptr, flags));
-    memcpy(lock_ptr, vb->data, len);
-    vb->d3d->Unlock();
+    if (lock_ptr) {
+        memcpy(lock_ptr, vb->data, len);
+        vb->d3d->Unlock();
+    } else {
+        xassert(0);
+#ifdef PERIMETER_EXODUS
+        fprintf(stderr, "D3D vertex buffer lock failed!\n");
+#endif
+    }
 }
 
 void cD3DRender::UpdateD3DIndexBuffer(IndexBuffer* ib, size_t len) {
@@ -1301,8 +1312,15 @@ void cD3DRender::UpdateD3DIndexBuffer(IndexBuffer* ib, size_t len) {
     void* lock_ptr = nullptr;
     uint32_t flags = ib->dynamic ? D3D_LOCK_FLAGS_DYNAMIC : D3D_LOCK_FLAGS_STATIC;
     RDCALL(ib->d3d->Lock(0, len, &lock_ptr, flags));
-    memcpy(lock_ptr, ib->data, len);
-    ib->d3d->Unlock();
+    if (lock_ptr) {
+        memcpy(lock_ptr, ib->data, len);
+        ib->d3d->Unlock();
+    } else {
+        xassert(0);
+#ifdef PERIMETER_EXODUS
+        fprintf(stderr, "D3D index buffer lock failed!\n");
+#endif
+    }
 }
 
 void cD3DRender::DeleteVertexBuffer(VertexBuffer &vb) {