Bug: Rhino makes .3DMBAK files despite option being unchecked

Hi All,

I have just started running Rhino on a new laptop (Version 5 SR8 64-bit, 5.8.40305.11495, 03/05/2014). Despite having unchecked the option to create backup files they are still produced. This has never occurred to me on previous laptops and I was wondering if this is a known bug?

I should say that this is a laptop from work/university which grabs a license from a server, perhaps this could make a difference. However this was also the set-up on my laptop at my old job.



Same problem here. That box is unchecked but the file still wants to be created.

I am working on a file in my Google Drive and when I finished the session I got an error message saying the file could not be renamed *.3dmbak. I clicked OK and the session closed. I lost all work from that session of the model. I believe this is due to GoggleDrive not completing the sync upload of the *.3dmbak file before I exited. When working with large files the sync can take a long time even on fast dsl.

I would prefer to define where that file is created so I can stash it out of the GoogleDrive folder.

Hi All- I am not sure what is going on but the 3dmbak file, I believe, is created regardless as part of the Save process, and deleted if the setting is unchecked. @AndersDeleuran are 3dmbak files created and left in place, can you tell?

@JohnM, do you have an idea? So far as I can see here, 3dmbak files are following the Options setting.


The problem for me occurred in the context of GoogleDrive which I use to keep current projects synched between my laptop and desktop. I am working with a 75MB model and save every 1/2 hour or so. In this instance I saved - got the error - and kept working. I was called away from my desk and quit the program 1/2 hour or so later and got the error again.
Since I had already clicked to close all I was presented with was a button for OK then Rhino was gone. The files that remained were over 1.5 hours old.
It would seem the save sequence is to first rename the .3dm file to.3dmbak - then save the .3dm file. If the rename can’t occur (due to locking in my case with gDrive in process of sync) no save occurs.
I would vote for no rename occurring if the checkbox for .3dmbak is cleared.

Hi Pascal. I am running a few tests now and am not able to reproduce the problem! I’ll keep an eye out and report back if the 3dmbak files start reappearing. Thanks, Anders

I now see this despite the option still unchecked, but it’s not every file.
Maybe it’s files on the network only?

I have the same issue here. Working from a google drive folder on my desktop:

Followed by:

I’ve seen this as well with large files on Google Drive - my current theory is that Google drive is busy synching, possibly, because it often works a short time later.


I think I’ve said this before, but this happens to me and all other users here when saving files directly to our university network drive. The first save of a new file works OK. After that I get:

Error replacing backup file “filepath_filename.3dmbak” with original file “filepath_filename.3dm” and original file “filepath_filename.3dm” with temp file "filepath\RHI6512.tmp"
Replace file function failed with error code 0.

That then leaves the .3dmbak file in place even though creating them is unchecked here as well.


I still run into this problem on a daily base, is there a solution already?

Anyone experience with the new Drive File System from google? (is for G suite only)

Yes… It’s called V6. :stuck_out_tongue_winking_eye:

It will not be fixed in V5, but appears to be working correctly (here at least) in the Beta.


Can anyone confirm that this will be fixed for good in Rhino 6?
Almost daily I encounter this 3dmbak annoyance with Google drive…

thx, Tobias

Do you save directly to a networked / cloud location?

I’ve always been told to save locally, like to my C: or D: drive … THEN LATER sync it to the cloud for back-up purposes.

I’m worried than any lag or interruption in my internet connection (never 100%!) will cause a very large file to get corrupted. The best case scenario is I only spend a lot of time waiting for save. Worst case is I lose the file.

Hi Dave,
I don’t save directly to the cloud (actually I don’t even know if that is possible). I am saving to a local folder on my computer and this folder is monitored and automatically synced with a cloud folder by Google Drive.
While syncing a file it gets locked by GD…

gr, Tobias