Possible Bug?

I’m not sure what’s going on with Rhino, but as of today I can no longer Import or Export without Rhino hanging temporarily or permanently. I thought it was permanently, but as I typed this Rhino finished the import and came back to life, other times required an End Process to get out.

I am running Win7 x64
Version 5 SR12 64-bit
(5.12.50810.13095, 8/10/2015)

I am happy to supply any additional information needed to troubleshoot.

I don’t know if it’s my system or Rhino. Rhino has always been solid as a ROCK for me, and I’m hoping that’s still the case.

Jeff Claunch

Hi Jeff - any plug-ins? Does the same operation work better if Rhino starts in safe mode?



No new plug-ins. Rhino lists SimLabSoft PDF Export Plugin as loaded. I think that’s it.

I will try safe mode here shortly and see what happens.

Thanks for the speedy reply!

Hi Pascal,

It seems to happen in Safe Mode too.

I think it’s probably a system problem as I’m seeing other issues now too, primarily with Saving. I have run disk diagnostics too with no luck finding a cause. Still searching for the problem…


Jeff, just as a test, open a fresh Rhino, run


and see if it behaves any better opening/saving etc…



I tested several previously failed import and export functions after testToggleFileDialog and no more failures.

What does this mean?


Hi Jeff- hmmm - for now, I think it means putting that command in the startup commands… @stevebaer - is there more of a fix? I cannot remember if there is anything more permanent.



I’ll happily throw that in the startup commands for now and keep an eye out for Steve Baer’s reply.

Thanks Pascal!

This typically means there is an ill behaved “Shell Extension” that is getting in the way. Unfortunately these can be pretty hard to track down and it is not something that Rhino has much control over. Shell extensions are programs that run when you show dialogs like the open and save dialog. The only program that I know of that can help with diagnosing is


Thanks Steve!

I’ll check it out.



I ran that program and found this as being the most recent extension installation. Timing makes sense too since I stated having trouble about that same time when I started using Outlook 2016. Do you think this could be related to the problem? If so, any suggestion of things to try next?

Thanks much!

Try disabling that extension and see if Rhino’s open and save dialogs work without running TestToggleFileDialog.


I did what you suggested and it seems everything is working properly now. I’ll keep testing and report back in a couple days.

Thanks a bunch Steve & Pascal, you guys rock!

Happy New Year!

Pascal & Steve,

Just to follow up. Everything here is working great after disabling that extension.

Thanks again you guys!!


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Thanks for letting us know; we’ll keep this in mind when other users run into this problem.