Cosmos can't open now? (libcef.dll error)

Corona for 3ds Max Corona for 3ds Max :: Issues
1

Hi, I installed the latest hotfix and now cosmos won’t load. tried re-installing, but this did not help. Any ideas?

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2

Can you please try uninstalling both Corona and Cosmos (it is listed in the Windows add/remove programs list) and then install Corona 15 HF1 again? If that doesn’t help, is the same thing happening with Corona 15 non-hotfix or 14?

3

Hi, thanks for the reply.

That didn’t help unfortunately.

I tried uninstalling again, resetting, re-installing. Still same error.

4

by any chance you have a antivirus and it deleted this DLL file?

5

libcef.dll is a library required to run Cosmos and it seems that it is already loaded by another plugin for you (not Corona). You can try the following:

  1. Load Corona as the only non-native 3ds Max plugin. You can go to Customize > Plug-in manager and disable any extra plugins you are using, then restart 3ds Max. If this works, perhaps you can find out which plugin is causing the conflict and disable it, at least when using Corona.
  2. Check the Windows PATH environment variables:
    1. Type “environment” in the Windows Start Menu
    2. Pick “Edit the system environment variables”
    3. Click “Environment variables”
    4. You will see two lists - “user” and “system”
    5. Locate an item called “Path” on both lists
    6. Double-click the one in the first list - you should get a list of folders. Open those folders one by one and check if any of them contains the file libcef.dll
    7. Double-click the one in the second list and do the same
    8. This way you should be able to locate an app which is loading the libcef.dll library in addition to the one required by Cosmos. You can uninstall that app (if possible) or move libcef.dll into a temporary folder so that it is not loaded, but note that this will most likely break the app which requires it (it might not start, show errors, or crash).

Hope this helps!

6

Hi again. Thanks for the tips. These did not work. I’m getting quite desperate now… now idea how to proceed? I gained some guidance from Codex. Here is what I’ve tried since:

  • Normal reinstall of Corona
  • Full uninstall/reinstall of all Chaos-related components
  • “Nuclear” cleanup: removed all Chaos software, deleted leftover folders manually, rebooted, reinstalled
  • Confirmed libcef.dll actually exists in the Corona 2025 folder
  • Confirmed Corona’s browser/CEF companion files are present (chrome_elf.dll, libEGL.dll, libGLESv2.dll, icudtl.dat, resources.pak, locales, etc.)
  • Reset 3ds Max 2025 ENU user profile
  • Tried plugin isolation / disabling other plugins in 3ds Max
  • Killed Chaos Cosmos Browser Service and tested again
  • Uninstalled a recently added overlay app (input-overlay), rebooted, tested again
  • Repaired Microsoft Visual C++ v14 Redistributable both x64 and x86
  • Ran modern Dependencies on Corona’s libcef.dll; it loaded successfully and did not show obvious missing dependencies

What seems ruled out:

  • Missing libcef.dll
  • Missing obvious companion CEF files
  • Broken VC++ runtime, at least at the obvious level
  • Chaos Cosmos Browser Service being the trigger
  • Recently installed overlay app being the trigger
  • Simple bad reinstall

Why I’m suspicious this may be Corona-side:

  • The issue started only after upgrading to the latest Corona 15/hotfix
  • Even after a full Chaos cleanup and reinstall, the same libcef.dll browser-component failure persists
  • Static dependency inspection of libcef.dll looks clean

If useful, I can also provide:

  • screenshots of the error
  • the Dependencies result
  • list of other libcef.dll copies on the machine from unrelated apps like Adobe / Spotify / SketchUp / NVIDIA / OBS

I’m on Windows 10. Any other tips? Thanks!

Edit: P.S. I did try your 1 point (Plug-in manager) - but I untick the plugins, restart max and they’re all ticked again. So I can’t test in this manner. How can I stop that from happening?

7

Sorry, I forgot to ask if you are able to use the workaround of launching Cosmos in your web browser at http://localhost:30305/

Please let me know if that works for you. Meanwhile, I will consult with our developers to find out what else we could try.

Regarding the plugin manager, sorry, looks like I was wrong and it is not possible to deactivate plugins that way.

8

Please check my previous message in this thread! ^

In addition to that, I have just created a support ticket #496773 for you. Please check your email.

9

Solved!

Deleting tyFlow_2025.dlo from the Plugins folder is what finally worked.

Thanks for all the help.

10

Just a note: it was an old tyFlow version - the new ones should not cause any troubles!