diff --git a/qrenderdoc/Windows/BufferViewer.cpp b/qrenderdoc/Windows/BufferViewer.cpp
index dfed72d0d..f68ff18ce 100644
--- a/qrenderdoc/Windows/BufferViewer.cpp
+++ b/qrenderdoc/Windows/BufferViewer.cpp
@@ -1453,6 +1453,9 @@ void BufferViewer::OnEventChanged(uint32_t eventID)
       guessSecondaryColumn(m_ModelGSOut);
   }
 
+  // needs to happen here so the mesh config is accurate when highlighting data is cached.
+  updatePreviewColumns();
+
   m_Ctx.Replay().AsyncInvoke([this, vsinHoriz, vsoutHoriz, gsoutHoriz](IReplayController *r) {
 
     BufferData *buf = NULL;
@@ -1502,8 +1505,6 @@ void BufferViewer::OnEventChanged(uint32_t eventID)
         m_ModelVSIn->buffers.push_back(buf);
       }
 
-      updatePreviewColumns();
-
       INVOKE_MEMFN(RT_UpdateAndDisplay);
 
       m_ModelVSIn->endReset();
@@ -1566,6 +1567,12 @@ void BufferViewer::RT_FetchMeshData(IReplayController *r)
     m_ModelVSIn->indices->data = (byte *)indices;
     m_ModelVSIn->indices->end = (byte *)(indices + draw->numIndices);
   }
+  else if(draw && (draw->flags & DrawFlags::UseIBuffer))
+  {
+    indices = new uint32_t[1];
+    m_ModelVSIn->indices->data = (byte *)indices;
+    m_ModelVSIn->indices->end = (byte *)indices;
+  }
 
   uint32_t maxIndex = 0;
   if(draw)
@@ -2103,6 +2110,9 @@ void BufferViewer::updatePreviewColumns()
       m_VSInPosition.idxbuf = ib.first;
       m_VSInPosition.idxoffs = ib.second + draw->indexOffset * draw->indexByteWidth;
 
+      if((draw->flags & DrawFlags::UseIBuffer) && m_VSInPosition.idxByteWidth == 0)
+        m_VSInPosition.idxByteWidth = 4U;
+
       {
         const FormatElement &el = m_ModelVSIn->columns[elIdx];
 
diff --git a/renderdoc/driver/d3d11/d3d11_analyse.cpp b/renderdoc/driver/d3d11/d3d11_analyse.cpp
index cbdee652e..64d90a517 100644
--- a/renderdoc/driver/d3d11/d3d11_analyse.cpp
+++ b/renderdoc/driver/d3d11/d3d11_analyse.cpp
@@ -2572,20 +2572,23 @@ uint32_t D3D11DebugManager::PickVertex(uint32_t eventID, const MeshDisplay &cfg,
 
     RDCASSERT(cfg.position.idxoffs < 0xffffffff);
 
-    D3D11_BUFFER_DESC ibdesc;
-    ib->GetDesc(&ibdesc);
+    if(ib)
+    {
+      D3D11_BUFFER_DESC ibdesc;
+      ib->GetDesc(&ibdesc);
 
-    D3D11_BOX box;
-    box.front = 0;
-    box.back = 1;
-    box.left = (uint32_t)cfg.position.idxoffs;
-    box.right = (uint32_t)cfg.position.idxoffs + cfg.position.numVerts * cfg.position.idxByteWidth;
-    box.top = 0;
-    box.bottom = 1;
+      D3D11_BOX box;
+      box.front = 0;
+      box.back = 1;
+      box.left = (uint32_t)cfg.position.idxoffs;
+      box.right = (uint32_t)cfg.position.idxoffs + cfg.position.numVerts * cfg.position.idxByteWidth;
+      box.top = 0;
+      box.bottom = 1;
 
-    box.right = RDCMIN(box.right, ibdesc.ByteWidth - (uint32_t)cfg.position.idxoffs);
+      box.right = RDCMIN(box.right, ibdesc.ByteWidth - (uint32_t)cfg.position.idxoffs);
 
-    m_pImmediateContext->CopySubresourceRegion(m_DebugRender.PickIBBuf, 0, 0, 0, 0, ib, 0, &box);
+      m_pImmediateContext->CopySubresourceRegion(m_DebugRender.PickIBBuf, 0, 0, 0, 0, ib, 0, &box);
+    }
   }
 
   if(m_DebugRender.PickVBBuf == NULL ||
@@ -2629,6 +2632,7 @@ uint32_t D3D11DebugManager::PickVertex(uint32_t eventID, const MeshDisplay &cfg,
   }
 
   // unpack and linearise the data
+  if(vb)
   {
     FloatVector *vbData = new FloatVector[cfg.position.numVerts];
 
diff --git a/renderdoc/driver/d3d11/d3d11_debug.cpp b/renderdoc/driver/d3d11/d3d11_debug.cpp
index c18a05a8c..ad31371cb 100644
--- a/renderdoc/driver/d3d11/d3d11_debug.cpp
+++ b/renderdoc/driver/d3d11/d3d11_debug.cpp
@@ -4982,7 +4982,7 @@ void D3D11DebugManager::RenderMesh(uint32_t eventID, const vector<MeshFormat> &s
     }
 
     m_pImmediateContext->IASetVertexBuffers(0, 2, vbs, str, offs);
-    if(ibuf)
+    if(cfg.position.idxByteWidth)
       m_pImmediateContext->IASetIndexBuffer(ibuf, ifmt, ioffs);
     else
       m_pImmediateContext->IASetIndexBuffer(NULL, DXGI_FORMAT_UNKNOWN, NULL);
diff --git a/renderdoc/driver/d3d12/d3d12_debug.cpp b/renderdoc/driver/d3d12/d3d12_debug.cpp
index df54597ce..0e74e2418 100644
--- a/renderdoc/driver/d3d12/d3d12_debug.cpp
+++ b/renderdoc/driver/d3d12/d3d12_debug.cpp
@@ -5519,18 +5519,21 @@ void D3D12DebugManager::RenderMesh(uint32_t eventID, const vector<MeshFormat> &s
         if(PatchList_Count(fmt.topo) > 0)
           list->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_POINTLIST);
 
-        if(fmt.idxByteWidth && fmt.idxbuf != ResourceId())
+        if(fmt.idxByteWidth)
         {
-          ID3D12Resource *ib =
-              m_WrappedDevice->GetResourceManager()->GetCurrentAs<ID3D12Resource>(fmt.idxbuf);
+          if(fmt.idxbuf != ResourceId())
+          {
+            ID3D12Resource *ib =
+                m_WrappedDevice->GetResourceManager()->GetCurrentAs<ID3D12Resource>(fmt.idxbuf);
 
-          D3D12_INDEX_BUFFER_VIEW iview;
-          iview.BufferLocation = ib->GetGPUVirtualAddress() + fmt.idxoffs;
-          iview.SizeInBytes = UINT(ib->GetDesc().Width - fmt.idxoffs);
-          iview.Format = fmt.idxByteWidth == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT;
-          list->IASetIndexBuffer(&iview);
+            D3D12_INDEX_BUFFER_VIEW iview;
+            iview.BufferLocation = ib->GetGPUVirtualAddress() + fmt.idxoffs;
+            iview.SizeInBytes = UINT(ib->GetDesc().Width - fmt.idxoffs);
+            iview.Format = fmt.idxByteWidth == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT;
+            list->IASetIndexBuffer(&iview);
 
-          list->DrawIndexedInstanced(fmt.numVerts, 1, 0, fmt.baseVertex, 0);
+            list->DrawIndexedInstanced(fmt.numVerts, 1, 0, fmt.baseVertex, 0);
+          }
         }
         else
         {
@@ -5620,18 +5623,21 @@ void D3D12DebugManager::RenderMesh(uint32_t eventID, const vector<MeshFormat> &s
     Vec4f colour(0.8f, 0.8f, 0.0f, 1.0f);
     list->SetGraphicsRoot32BitConstants(3, 4, &colour.x, 0);
 
-    if(cfg.position.idxByteWidth && cfg.position.idxbuf != ResourceId())
+    if(cfg.position.idxByteWidth)
     {
-      ID3D12Resource *ib =
-          m_WrappedDevice->GetResourceManager()->GetCurrentAs<ID3D12Resource>(cfg.position.idxbuf);
+      if(cfg.position.idxbuf != ResourceId())
+      {
+        ID3D12Resource *ib =
+            m_WrappedDevice->GetResourceManager()->GetCurrentAs<ID3D12Resource>(cfg.position.idxbuf);
 
-      D3D12_INDEX_BUFFER_VIEW view;
-      view.BufferLocation = ib->GetGPUVirtualAddress() + cfg.position.idxoffs;
-      view.SizeInBytes = UINT(ib->GetDesc().Width - cfg.position.idxoffs);
-      view.Format = cfg.position.idxByteWidth == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT;
-      list->IASetIndexBuffer(&view);
+        D3D12_INDEX_BUFFER_VIEW view;
+        view.BufferLocation = ib->GetGPUVirtualAddress() + cfg.position.idxoffs;
+        view.SizeInBytes = UINT(ib->GetDesc().Width - cfg.position.idxoffs);
+        view.Format = cfg.position.idxByteWidth == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT;
+        list->IASetIndexBuffer(&view);
 
-      list->DrawIndexedInstanced(cfg.position.numVerts, 1, 0, cfg.position.baseVertex, 0);
+        list->DrawIndexedInstanced(cfg.position.numVerts, 1, 0, cfg.position.baseVertex, 0);
+      }
     }
     else
     {
diff --git a/renderdoc/driver/gl/gl_debug.cpp b/renderdoc/driver/gl/gl_debug.cpp
index b15dfb2b2..240358513 100644
--- a/renderdoc/driver/gl/gl_debug.cpp
+++ b/renderdoc/driver/gl/gl_debug.cpp
@@ -2978,7 +2978,7 @@ ResourceId GLReplay::RenderOverlay(ResourceId texid, CompType typeHint, DebugOve
             gl.glEnableVertexAttribArray(0);
             gl.glDisableVertexAttribArray(1);
 
-            if(postvs.idxbuf != ResourceId())
+            if(postvs.idxByteWidth)
             {
               GLenum idxtype = eGL_UNSIGNED_BYTE;
               if(postvs.idxByteWidth == 2)
@@ -4811,7 +4811,7 @@ void GLReplay::RenderMesh(uint32_t eventID, const vector<MeshFormat> &secondaryD
 
         GLenum secondarytopo = MakeGLPrimitiveTopology(fmt.topo);
 
-        if(fmt.idxbuf != ResourceId())
+        if(fmt.idxByteWidth)
         {
           GLuint ib = m_pDriver->GetResourceManager()->GetCurrentResource(fmt.idxbuf).name;
           gl.glBindBuffer(eGL_ELEMENT_ARRAY_BUFFER, ib);