Unable to Lock Global Memory Block on Rhino 5

Hi everyone,

So recently I’ve been trying to copy and paste objects into my model but I keep getting this message:

Write3dmViaTempFile() - Unable to lock global memory block.

This hasn’t happened to me before. I’ve seen on other forum that if you reset your computer that error should go away but doesn’t for me. Could someone help me out please? For reference my Rhino is V5 (64-bit), on Window of course.

Much appreciated,

Hi Tracy - could you post a 3dm file and specific steps to reproduce that error?

Write3dmViaTempFile() - Unable to lock global memory block.

I am facing the same problem, but restarting rhino or reinstalling rhino didnt help me.! please help if u know the solution.

thank u.

Hello did anyone managed to solve this problem
Write3dmViaTempFile() - Unable to lock global memory block.

Got the same report from a user. I found some posts about this problem, but there was not a clear solution. Here’s how the problem was detected and fixed.


  1. Ran Process Monitor on the computer.
  2. Set up a filter to only display the processes that access the TEMP folder.
  3. Copied an object in Rhino to make the error happen.

Every time the error happened in Rhino, the SAntivirusService also accessed the TEMP folder. (It locked Rhino’s clipboard temp files.)

SAntivirusService is from sAntivirus Protection Lite. It could be installed by some freeware. It may be identified as malware by antivirus applications.

When Windows in the normal mode…

  • I was not able to uninstall it because its uninstaller.exe was detected as a virus and was locked (by itself?).
  • I was not able to turn its services off.
  • I was not able to delete its files or registry keys. All locked.

When Windows in the safe mode…
The uninstaller.exe could be run. It could not uninstall the application successfully, but I was able to delete all of its files in C:\Program Files (x86) and its services in Windows Registry under \KEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ and this was the fix.