I've just experienced this bug for myself. I have an assembly with 16,721 components and the Bill of Materials, is slow to load and when it does, both the Model Data and Structured tabs are blank, yet the Parts Only seems fine.
I am using Inventor Professional 2025.0.1, Build 162.
Since opening the assembly, other than correcting a few broken constraints, I have demoted two sub-assemblies. No copy design performed and we don't use Vault. Also, no ipt and iam mix up.
Given what I've read here, perhaps the demotion was the issue. Did anyone here get to the root cause? Is there an easy and quick way to tell which sub-assembly is corrupted?
Following the advice from @johnsonshiue in post #4, I tried the following:
In the first sub-assembly, I promoted the components back out. Then tried to open the BOM. Still blank.
I used undo to place those components back as I need them.
In the second sub-assembly, I promoted the components back out and tried to open the BOM. Still blank.
With the components from the second sub-assembly still promoted, I hit save, then checked the BOM. Still blank.
Deleted the empty sub-assembly. Hit save and checked the BOM. Still blank.
Promoted the components out of the first assembly again. Hit save and checked the BOM. Still blank.
Deleted the empty sub-assembly. Hit save and checked the BOM. Still blank.
Used 'Place' to re-insert my two empty sub-assemblies back into the top level. BOM still blank.
Had to open each of the empty sub-assemblies and place a random part into it before I could return to the top level assembly and drag the original components in the browser tree, to demote them back in. Hit save after re-creating each sub-assembly. BOM still blank.
Closed the whole assembly. Closed Inventor. Restarted and re-opened the assembly. BOM still blank.
I'm at a loss where to look next.
The only other detail I can think to share, is that the components that I am demoting and promoting are hydraulic cylinders, which are flexible assemblies themselves. We buy these cylinders off-the-shelf and then weld a small tab to them, so I wanted to reflect that in the models. Hence demoting them. When demoted, I obviously had to change the new sub-assembly to flexible too and I wasn't sure how Inventor would handle this. However, that functionality seems to work fine.
Ultimately, I need to update a drawing of my top level assembly, which has a parts list that is missing loads of lines, so until I can find a fix to this, I am stuck. Any suggestions would be welcome.
Many thanks
Steve
