ZBrush 2021.6 Does Not Launch and No Error Message

Win 10 here and get ntdll.dll error which is reported in the event log. Can’t start ZB at all:(

I install 2021.6 with the upgrade.exe in the Zbrush-Program folder of Zbrush 2021.5.1.
Everything went fine. but Zbrush 2021.6 wouldn’t start now. It begins loading and then stops and disappears. Anyone got an idea what went wrong?

(Note: This is different from the “missing dll” error that comes up for Windows 7 and 8.0 users.)

We have learned that for most users this is caused by your antivirus software not recognizing the new ZBrush version as safe. This is something that will go away naturally over time as antivirus programs learn that ZBrush 2021.6 is indeed a safe application. Until then, there are multiple ways for you to resolve the issue.


A) Use whatever tool your antivirus software has for designating the ZBrush.exe as being “safe” or “trusted.”


B) Delete or rename your ZBrushData2021 folder. On Windows it’s located in C:\Users\Public\Public Documents. On macOS it’s in /Users/Shared.

That should resolve the issue for you. If it does not, please try a full reinstall of ZBrush. This is not the same thing as a regular uninstall/reinstall. It involves removing some files manually.

Follow these steps to perform a clean installation and get ZBrush activated:

  1. Uninstall ZBrush from your computer.
  2. Locate and delete the ZBrush folder that is left behind. (It’s found in a Pixologic subfolder in your Program Files or Applications directory.)
  3. If you are on Windows locate and delete the \Users\Public\Public Documents\ZBrushData20XX folder. If you are on Mac locate and delete the \Users\Shared\ZBrushData20XX folder. (The ZBrush20XX refers to the version you’re reinstalling, such as ZBrushData2020.)

Note: For Mac users, the easiest way to get to \Users is to be in the Finder and click Go at the top of the screen, then Computer in the pull-down menu. Now in the window that opens, double-click on Macintosh HD. You’ll then see Users as one of the folders.

  1. Make sure you are logged into the computer as an admin user and disable your antivirus software. (This includes Windows Defender!)
  2. Now you can download and install the ZBrush full installer by logging into your Pixologic ID account at the My Licenses portal:
    Pixologic :: My Licenses
  3. Once done installing, launch the software and choose the Web Activation method to get activated.
  4. After you have activated ZBrush you can turn your antivirus software back on.

Thank you!

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