ZBrush Won't Start: Side-by-Side Configuration Error and Visual C++ Runtime Fix

ZBrush Won't Start: Side-by-Side Configuration Error and Visual C++ Runtime Fix

I got a call from a new hire last week: "ZBrush won't open. It says 'side-by-side configuration is incorrect.' I've reinstalled it twice." This error has been around since ZBrush 4R3, and it's still one of the most common startup failures I encounter. The good news is that it's not a ZBrush bug — it's a Windows dependency issue, and the fix is straightforward once you understand what's happening.

What "Side-by-Side Configuration" Actually Means

Windows uses a technology called Side-by-Side (SxS) assemblies to manage DLL dependencies. When ZBrush launches, Windows checks a manifest file embedded in ZBrush.exe that lists the exact versions of Visual C++ runtime DLLs it needs. If those DLLs aren't present — or if the wrong version is present — Windows refuses to launch the application and throws the "side-by-side configuration is incorrect" error.

The error message says "Reinstalling the application may fix this problem," but reinstalling ZBrush rarely helps because the missing dependency is a Microsoft runtime, not a ZBrush component.

Fix 1: Install the Correct Visual C++ Redistributable

This fixes the issue 90% of the time. The specific version ZBrush needs depends on which version of ZBrush you're running:

For ZBrush 2021 and later:

1. Download Microsoft Visual C++ 2015-2022 Redistributable (x64) from Microsoft's official download page
2. Install it, then restart your computer
3. Try launching ZBrush again

For older ZBrush versions (4R7, 4R8):

1. Download Microsoft Visual C++ 2008 Redistributable (x86) — note the x86 architecture, even on 64-bit Windows
2. Also install Microsoft Visual C++ 2010 Redistributable (x86)
3. Restart and try ZBrush

I keep a folder of all Visual C++ Redistributables on our network share. When setting up a new workstation, I install them all before installing any creative software. This prevents not just ZBrush startup errors but also issues with 3ds Max, Substance Painter, and other tools.

Fix 2: Use SxsTrace to Identify the Exact Missing Dependency

If installing the Visual C++ Redistributable doesn't fix it, you need to find out exactly which assembly is missing. Windows has a built-in tool for this:

1. Open Command Prompt as Administrator
2. Run: sxstrace.exe Trace -logfile:sxs.etl
3. Try launching ZBrush (it will fail with the error)
4. Go back to Command Prompt and press Enter to stop tracing
5. Run: sxstrace.exe Parse -logfile:sxs.etl -outfile:sxs.txt
6. Open sxs.txt and look for the error message

The output will tell you exactly which assembly is missing. For example:

Activation context generation failed for "C:\Program Files\Maxon\ZBrush\ZBrush.exe".
Dependent Assembly Microsoft.VC90.OpenMP,processorArchitecture="x86",
publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.21022.8"
could not be found.

This tells you that ZBrush needs the Visual C++ 2008 OpenMP runtime (x86). You can then download that specific redistributable from Microsoft.

Fix 3: Check the Windows Event Viewer

The Event Viewer provides similar information to SxsTrace but is easier to read:

1. Right-click Start → Event Viewer
2. Navigate to Windows Logs → Application
3. Look for "SideBySide" errors with the timestamp matching your ZBrush launch attempt
4. The error details will name the missing assembly

I check the Event Viewer before running SxsTrace because it's faster and the information is usually sufficient.

Fix 4: Repair Existing Visual C++ Installations

Sometimes the Visual C++ Redistributable is installed but corrupted. Instead of reinstalling:

1. Go to Settings → Apps → Installed apps
2. Search for "Visual C++"
3. You'll see multiple entries — find the one matching ZBrush's requirement
4. Click Modify → Repair
5. Restart the computer

I've seen cases where a Windows update corrupted the Visual C++ runtime, and a repair fixed it when a fresh install didn't.

Fix 5: Clean Reinstallation of ZBrush

If all else fails, a clean reinstallation of ZBrush ensures the correct manifest and dependencies are in place:

1. Uninstall ZBrush via Windows Settings
2. Manually delete the ZBrush installation folder: C:\Program Files\Maxon\ZBrush (or C:\Program Files\Pixologic\ZBrush for older versions)
3. Delete the ZBrush data folder: C:\Users\Public\Pixologic\ZBrushData
4. Open Registry Editor and delete: HKEY_LOCAL_MACHINE\SOFTWARE\Pixologic and HKEY_CURRENT_USER\Software\Pixologic
5. Restart the computer
6. Install ZBrush fresh
7. Install all Visual C++ Redistributables before the first launch

This is the nuclear option, but I've never seen it fail when the issue is purely a side-by-side configuration problem.

Fix 6: Windows Reset (Extreme Cases)

I had one case where a user's Windows installation had accumulated so many corrupted SxS assemblies that no application would launch — not just ZBrush. The Windows component store itself was damaged.

The fix: Run DISM /Online /Cleanup-Image /RestoreHealth from an elevated command prompt. This repairs the Windows component store, including all SxS assemblies. If DISM can't fix it, a Windows reset (Settings → System → Recovery → Reset this PC → Keep my files) is the last resort.

Preventing the Error on New Installations

My workstation setup checklist now includes:

1. Install all Visual C++ Redistributables (2005, 2008, 2010, 2012, 2013, 2015-2022) — both x86 and x64
2. Install ZBrush
3. Launch ZBrush once to verify it starts correctly
4. Run Windows Update to get the latest runtime updates
5. Create a system restore point for easy rollback if a future Windows update breaks the runtimes

I also create a batch script that silently installs all Visual C++ Redistributables in sequence. This ensures no version is missed and the installation is repeatable across multiple workstations. The script installs each redistributable with the /quiet /norestart flags, which means no user interaction is required and no reboots interrupt the process. I keep this script on our network share alongside the redistributable installers, so any IT team member can set up a new workstation without missing a dependency.

Another preventive measure: I image the workstation after the initial setup is complete. This way, if a Windows update corrupts the SxS assemblies, I can restore the image in 20 minutes instead of spending hours troubleshooting DLL errors. The image includes all Visual C++ runtimes, ZBrush, 3ds Max, and all other studio software — pre-configured and tested.

Common Misdiagnoses

I've seen IT departments waste hours on the wrong fixes for this error:

Misdiagnosis 1 — "Reinstall ZBrush": The error message literally says "Reinstalling the application may fix this problem," so this is the first thing everyone tries. It rarely works because the missing component is a Microsoft runtime, not a ZBrush file. I've seen users reinstall ZBrush 5+ times before contacting me.

Misdiagnosis 2 — "Run as Administrator": Some IT techs suggest running ZBrush as Administrator to bypass the side-by-side check. This doesn't work — the SxS system operates at the Windows level, not the user level. Administrator rights don't change which assemblies are registered.

Misdiagnosis 3 — "Disable antivirus": Antivirus software can sometimes block application launches, but the side-by-side error is specifically about missing DLL dependencies, not blocked executables. If the error message mentions "side-by-side configuration," it's a dependency issue, not a security issue.

Misdiagnosis 4 — "Update Windows": While Windows updates can sometimes fix SxS issues by updating the component store, a generic Windows Update won't install the specific Visual C++ Redistributable version that ZBrush needs. You need to download and install the exact version identified by SxsTrace or Event Viewer.

When to Contact Maxon Support

If you've tried all the fixes above and ZBrush still won't launch, it's time to contact Maxon support. Before contacting them, gather this information:

1. SxsTrace output — the exact missing assembly name and version
2. Event Viewer error details — the full error message from the Application log
3. Windows version — run winver and note the version and build number
4. ZBrush version — check the installer file name or your Maxon account
5. List of installed Visual C++ Redistributables — go to Settings → Apps and list all "Visual C++" entries

Maxon support can provide version-specific guidance and may have seen the exact issue on other systems. I've contacted them twice for unusual SxS errors, and both times they provided a specific redistributable version that resolved the issue.

Summary

The "side-by-side configuration is incorrect" error is a Windows DLL dependency issue, not a ZBrush problem. Install the correct Visual C++ Redistributable (check SxsTrace or Event Viewer for the exact version), repair existing installations if needed, and do a clean ZBrush reinstall as a last resort. I prevent it entirely by installing all Visual C++ runtimes before any creative software on new workstations, and I maintain a batch script and system image for rapid deployment. Don't waste time on common misdiagnoses — if the error says "side-by-side," it's a dependency issue that requires a specific runtime installation.