A cyclical constraint dependency was detected

[w.poortinga]

Hi,

My inventor MB part has the EOP slider somewhere in the middle. For some reason I can't make any changes to my part anymore. Can't move the EOP. Can't edit a feature above the EOP, nothing.

Everything shows me the 'A cyclical constraint dependency was detected' error. On both Inventor 2020 and 2021.

Can someone help me? I'm afraid the part is corrupted? Is this a known error?

I can make a new part and derive this one, but I need to make changes to the original part which I now can't make.

[WHolzwarth]

Not much can be done, without looking at the IPT file.

[mdavis22569]

Can you share the file .... but likely there some corruption in it.

Do you have a back up / old version of it that you can recover?

[j.palmeL29YX]

Can you upload the part?

I'm afraid you must not. Or maybe you do?

[w.poortinga]

Ah ofcourse. I just checked out an older version in the Vault. Will upload the broken file later so you guys can take a look at it, I'm in a hurry to finish my project first. Thanks for the replies!

[johnsonshiue]

Hi! This must be a bug. Basically, one or more constraint (dimension) in a sketch depends on geometry created after the sketch. This is wrong. But, the tricky thing is that we need to find out how the condition started.

Try a few things. Right-click on the sketch -> Redefine -> select the workplane or planar face. Or, delete the projected origin center in the sketch. In some cases, neither is an option. Please share the file here. Forum experts can help take a look.

Many thanks!

[llorden4]

@johnsonshiue 

I'm expanding deeper into API and creating sketches and ran into this issue.  Not very far into development here but I'm now no longer even able to use this file as any attempt to do anything results in this error.  Even with the iLogic rule now suppressed, I can't delete the created sketches or features created.  Closing the file isn't even an option and must exit Inventor via Task Manager.

My screen is now in a constant swap between these two warning boxes.

In the number of threads I've found on this error, the main question coming is trying to figure out how the condition was created.  I'm attaching the file with the current state of iLogic code that was included prior to this lockout.  I have several 'REM'd out statements that were testing well prior to this issue.

Hopefully you can use this file as a test bed to isolate why this bug is coming up.

[llorden4]

FYI, copied all the parameters & iLogic into a fresh blank template and ran without issue.  Reporting in case this helps with troubleshooting.

[johnsonshiue]

Hi Leonard,

The part seems corrupted. There are ghosted body nodes left in the database. It looks like it has been edited (reordering features) quite a bit. To avoid the error, you can edit "Hollow Sketch" and delete the vertical dimension of 6 at the top. After that, the error will go away. However, the corruption sustains.

I notice that the part was created from scratch in 2021. Do you know a way to reproduce the behavior?

Many thanks!

[llorden4]

@johnsonshiue 

Not really, like I said I'm figuring how to create sketches now with iLogic and I'm re-running the rule many times over to test a new line(s) of code to see how it performs and if it does what's expected.  I have the code erasing all existing features & sketches before restarting each time, a clean slate if you will, probably the source of your dirty pool.

[johnsonshiue]

Hi Leonard,

I think we may have defects there. Do you mind sharing the iLogic code or API code with me directly johnson.shiue@autodesk.com? I would like to see if I can reproduce the corruption.

Many thanks!

[llorden4]

@johnsonshiue 

Sure, scroll back up to Message #7.  It's already attached.

[johnsonshiue]

Hi Leonard,

Yes, I know about that part. I tried it and concluded that it was corrupted. I saw the rule. But, I need the new part and the rule to run. I suspect there are bugs in our API or some core functionality leading to the corruption. I want to reproduce it from scratch.

Many thanks!

[gerrardhickson]

Hi all,

I had the same problem yesterday with a part - there was lots of up and down with the EOP slider in that part, (manifold.ipt attached), then again today, the same problem with a much more simple part (Mount.ipt attached).

Both parts appear to be corrupt - I can no longer make any changes at all.

With Manifold.ipt, there were dozens of steps to get the error, mostly with trailing and erroring in the loft features, but with the mount.ipt part it was quite simple. I started with Mount (Original).ipt attached, which is a multi-body part - then I moved the EOP back to the top, and progressively moved it down joining each feature to the first solid body, and editing/erasing features that became sick. I made it to "Extrusion10" when the error occurred.

I've tried the exact same steps again (listed below), and the same problem occurred.

• Open Mount (original).ipt  - note, on my system this name was different. 
• Save as a new .ipt
• Move EOP to below "Extrusion 3"
• Move EOP to below "Extrusion 5"
• Edit "Extrusion 5" to join body and select small rectangular profile to fill in the cut section.
  
• Move EOP below "Fillet 6"
• Move EOP below "Chamfer 1"
• Suppress "Fillet 11" through to "Chamfer 1"
• Edit "Extrusion 10" to join body
• Insert new chamfer - select edge shown below, set chamfer distance to 12mm 
• 

  Click OK - and you'll get the error.

I have only just updated Inventor in the last few days so it's up to date.

Inventor version info:

Hope this helps some how.

[SBix26]

@gerrardhickson  Attached is your Mount (original).ipt converted into a single solid (2020 format).  It took a bit of investigation, re-ordering some features, but got the job done.  Instead of working from top to bottom, I kind of worked from both ends.

With all the dependencies, it was a matter of trial and error to see what would work.

---

Sam B
Inventor Pro 2021.1 | Windows 10 Home 2004
LinkedIn

[gerrardhickson]

Hi @SBix26,

Yeah, I'm sure it's do-able. The point was just to provide the steps to recreate in case @johnsonshiue or others can find the cause of the problem.

For that particular part, I just started again - it's not a particularly challenging part....

Thanks though.

[johnsonshiue]

Hi Gerrard,

Many thanks for sharing the files! I see the behavior. Indeed, this is a corruption. It means a parent sketch/feature depends on a child sketch/feature. The source is unknown. I am not sure if you still remember how it got to this state. Unfortunately, there isn't much we can do for a file like this. You may want to rebuild the part from scratch. You could copy the sketch/feature and paste to another part. I am sorry!

Thanks again!