Regular History regeneration failures

I have been a user of ZW3D for many years and have constantly been plagued with History regeneration failures. When I want to rework a feature or sketch in a LONG history tree, i get a lot of RED failed features and have to undo the regeneration .

I always thought it may be a ZW3D problem and I must wait for the next SP or get the next Upgrade, but with each SP and Upgrade I get the same issues.

Do I need to change my procedure, method or design intent to eliminate this from happening to me, or are others also experiencing the same issues?

Hi Alan,

All parametric CAD programs need a careful and thoughtful strategy when doing complex design, including ZW3D, but even if you’ve done your best doing that, modifying a feature in a long history can still cause conflicts with others. The system usually tells you why in the Output window, and that’s where you can start to fix the issues.

So that’s just the nature and daily life of any parametric CAD program, at least to me.

It’s just my opinion and maybe others can provide a better idea about how to avoid this.



certainly history problems have been a constant headache especially before 2020, where they have improved outside but there are still problems.
Particularly, to be able to keep working with geometry, when the tree has been a problem, I don’t waste any more time. I encapsulate and sacrifice the tree.
As I do not make product families or need to parameterize, I make changes with direct editing. The other problem is that direct editing doesn’t work properly very often, so I work with surfaces.
I survive as best I can.

Thanks for explaining that, I will take the idea of “encapsulating and sacrificing the History tree”. Do I do that by saving it as a NEUTRAL File and then work from that?

Thanks Acon, it is good to hear it is not only me experiencing this problem.
I think it will always be easier to use the CAD program and get problems than it is to deign and develop a trouble free CAD Software System


Hi Alan,
I do a some very complex designs where the models are 5 versions old. A single shape could have 400+ history objects.
Each new version of ZW3D has meant a rebuild of the history needing fixes and occasionally replacing a process.
Reliability has steadily improved. In 2020 I am seeing a very high level of reliability when the modelling is stable.
My current theory is that correct modeling methods are important in achieving stability.
It can depend a lot on how you use references. These and fillet fails due to upstream edits are teh most common issues. Almost always it is the result of chain references or internal clutter in the database.
The Root Object ‘Clean’ and ‘Fix’ tools are very useful.

If you had a problematic model you could share then a review of the processes you use could be enlightening?

Cheers - Paul

Thanks Paul, I will be able to send you a file to try out.
Shall I save it in the FAILED format, or will you try to do History regen yourself?


Hi Alan,
failed is good.
An annotated Screen shot of the problem as it appears on your screen might be useful too.

Cheers - Paul

Hi Paul, I didn’t have time to go through my files to find a FAILED history, BUT i am busy with Electrodes for this mould and during my SURFACING operations I started to get failures with Sweep or surface between sketch to sketch .
At the moment, I cant even open the ZW file that has the issue, but I can open the other objects within the same file.

Hi Alan,
which specific part and operation is problematic?
A screen shot highlighting the history would be a start.
BTW All opened OK.
Cheers - Paul

zw3d file not opening even for preview

Hi Paul, are you opening the file in ZW3D 2021 version?(please save a STEP file and place in dropbox)
I have attached a screen shot of how my screen is locked with ZW3D file not opening even for preview.
I cant even go and choose the other models as the program is jammed.
When I close it and then restart ZW3D the file opens and i can pick the other models with a preview, but as soon as I click on the top file the program jammes up again.


Hi Alan, opened with 2020. Not using 2021 yet - too busy.
I suggest you do a back up of your User Folder then do a Clear of your User folder and restart.
I also ran the File Clean and Fix Tools in Root Object. Only a couple of issues resolved. Otherwise looks fine to me.

Some aspects of the file I do not understand.
Like why are there 3 Mass inquiries at the beginning of the history yet no feature for importation of the shape?
Are you using the Assembly Reference tools at all ? Becuase I cannot see a history it is hard to tell what is taking place.
But looking at the combo of surfaces and shapes I suspect there is simpler way for you to model these.
Cheers - Paul

When I learned to use (ahem) NX at one of my previous employers they looked long and hard at regeneration failures and we were taught to model in very specific methods that had the effect of making the models more robust. It took longer to make models and they had far longer history trees but when models were altered it had the effect of crashing a single feature rather than the whole model.

Learning only few months in February 2021 I have had few of these problems too. After trying many different things I found, that if you create components out of the solids( by extract shape command) as you go, it is necessary to go into Assembly/Component manager and shut of visibility of these components, as it is displayed simultaneously with solids and covering them up. Now changes to geometry you do might think are done to the solid you intent are actually done to component and it will not reflect in the solid. The solution was: each time you create component from solid by Extract shape command, regenerate and then go into Assembly/Component manager(second icon down on top left vertical menu) and shut the visibility of the components off and return to history manager to continue your work… Each time you make a change to any solid in your tree, run rebuild/regenerate command, it will update the existing components. Again check in the Assembly/component manager and make sure the visibility of the component is turned off, then return back to history manager and continue.
If you have existing complex file, use the history divider (red line at the bottom of the history tree), move it up and do partial regenerate and continue moving down until you find out, where the problem is and fix it. Most likely you have modified component instead of your solid and now there is a conflict in the shape…that is my experience so far.