Rhino help: flash movie script error under windows 10

Clicking the embedded flash movies in rhino help leads to a script error under windows 10 (see attached picture, sorry for German error message).
Clicking to run the script, leads to the download of Adobe flash updater and to another error message telling me that Microsoft edge already contains the latest flash version.
This happens every time a movie in a help page is played for the first time.
Going to another page, then returning to a page where movies have already been played and replaying movies will initiate the whole thing again.
Very, very annoying!

I really don’t know why, but Rhino help has always been the only platform that has giving me constant problems with movie playback: under windows 7/8 several versions of flash player were needed to be installed, now under windows 10 this update loop garbage.
Easily one of the most irritating parts of the whole rhino experience. Sorry if this sounds like a rant.

Cheers, Norbert


Hi Norbert,

Sorry for replying late. I’m sorry that you are having the problem. Looks like you run Rhino in English. Please open the following location on your computer:


Rename the RhinoHelp.chm in the folder to anything else.

Rhino will load the help content from http://docs.mcneel.com/rhino/5/help/en-us/index.htm that uses mp4 videos.

I’ll report the problem about flashplayer to our developers. Thanks for reporting this.

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I’m not at my workplace for the next couple of days.
Will try your workaround when I’m back and let you know if it worked.
Thank You again, cheers.

Hi @KelvinC
I just wanted to let you know, that your workaround did the trick.

Sure this needs to be fixed though, if only to make the help movies accessible offline.
(or is it possible to download the complete mp4 help files from docs.mcneel.com and get it to work offline?)
Why doesn’t the help viewer use mp4 movies?
To me Flash really does feel out of date, doesn’t it?
After all it’s not the 90s anymore…:grin:


Hi @norbert_geelen,

Rhino 5 help documents (html files) were compiled into a chm file that we have dropped developing. Lots of html code editing will have to be involved if we want to make the chm to play local mp4 videos and we don’t know if it’s going to work.

I’m testing the problem on a fresh English Windows 10 and notice the flash videos in the help topics can be played. I have no idea why it doesn’t work on your computer and one of my computers. I’ll try to figure it out.

Had the same thing on my fresh install on Windows 10.

But then that actually triggered the installation the flash player (sorry wasn’t able to capture the screen), I get the following:

Unfortunately it doesn’t install correctly. So every time I try to run the Help it does the same thing…

Not very encouraging…



Hi Mitch,
Exactly the behavior I described.
I just didn’t provide the last two screenshots.


I reported the problem to Youtrack using @Helvetosaur’s screenshots, thanks.


I noticed the flash videos can play if you open the RhinoHelp.chm outside of Rhino.

In the online version of the help, the Flash videos have been replaced with mp4. I don’t think I can do anything to fix the .chm file at this point. If this becomes a huge issue for people who do not have online access, we will have to do something to fix this, but for now, as stated before, if you delete the .chm from your computer (or rename it), Rhino will automatically call the online version instead of the .chm. Keep me advised of how widespread this problem is.

Hi Margaret.
Personally, I can live with this workaround.
I just hope this will be fixed for version 6.
Cheers, Norbert

How do you open it (what program do you use?)


You can double click the RhinoHelp.chm to open it. chm format is associated with C:\Windows\hh.exe by default unless the association is lost.

Just experienced the same issue on Windows 8.1 Pro
I just entered “Yes” when the dialog appeared. From that point onwards I was able to play .chm files.

Unfortunately I get the same error after launching RhinoHelp.chm by double-clicking on it then trying to play the .chm files. Has there been any solution since this was reported?

For Rhino 5, you can delete this Help folder

Rhino will load the help topics online to the Help panel, or when you press the F1 key.

To read the help topics offline, you can download Rhino5_Help_en-us_mp4.zip
Extract the topic files from the zip file to a folder, and open the index.htm.

There is no other solution because Flash Player is no longer supported by Windows system.

Thanks Kevin

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