INV 2026_Severity Error when loading .iam files.

[uday3C]

Hi all,

In most of my parent assemblies that reference very large .ipt files (converted from .step), I'm encountering the following recurring error:

severity: SEVERITY_ERROR, facility: <Unknown Facility> ($FFFFFFFF)

(I've attached screenshots showing this issue across several files.)

What's odd is that this error consistently affects only the “heavy” .ipt files. Other .ipt files in the same project work fine. However, any .iam assembly connected to/with these large .ipts also shows the same error.

I’ve attempted to roll back to older revisions, but those versions are missing the progress I've made on the affected parts.  Also, strangely enough, for all the files that are affected, no iProperties can be loaded from the Windows Explorer. 

For context, I'm running Inventor 2026 and have updated to the latest build [Build: 175, Release: 2026.0.1]. Unfortunately, I can't share the actual files since they contain sensitive client information.

I'm leaning towards file corruption due to storage disk error OR RAM error while saving the files during an instance. Has anyone else encountered such an issue? 

Thanks in advance for your help!

[johnsonshiue]

Hi! The error message usually indicates some sort of corruption. If possible, please share the files in zip here. I would like to understand the corruption better. I can also try using our internal debug tool to see if it can salvage the files.

Many thanks!

[uday3C]

@johnsonshiue,

Sorry, but I cannot share the files here, in the public domain. Can you please share your contact details to share the model data with you directly?

Thanks for the help!

[johnsonshiue]

Hi! Certainly, please share the files with me directly at johnson.shiue@autodesk.com. I am more than happy to take a look and share my findings with you.

Many thanks!

[uday3C]

Hello @johnsonshiue,

I've sent you an email with the model and some additional context to the files in question. Hope you have received the email.

Thanks!

[johnsonshiue]

Hi! Just to provide some update regarding the issue, I did receive the files Uday shared with me. Without disclosing the detail, I can share my findings as the followings. All Inventor files are compressed files. Certain segments and folders must be present in the files. However, the segments and folders are missing and there are segments with cryptic names.

It seems that the files were rearranged or recomposed by a tool. They are corrupted. I don't have a way to salvage the corrupted files unfortunately.

Many thanks!

[uday3C]

@johnsonshiue, thanks for reviewing the 3D model.

Have you encountered such an issue before and what might cause such a rearrangement of the file internals? Does such a thing happen when errors occur during file movement from one drive to another?

Regardless, we have had a design iteration over the week, so rebuilding the model was inevitable, though it would have been good to have the old model, which seems to have been corrupted. 

Also, with the new model, we have decided to separate the structure, piping, electrical, and outfitting into different models (projects) just to ensure no such thing happens in the future.

Thanks for the help!

[johnsonshiue]

Hi! I have seen this error message before but I am not aware of a reproducible workflow leading to the corruption. Unfortunately, there isn't any progress made on preventing or salvaging the corrupted files of this type.

Many thanks!

[kanchha87]

hi I am facing same issue severity_error, facility: <Unknown Facility> ($FFFFFFFF) in inventor 2026. In older version never face like this issue. New update really killing me. Also 

I'm experiencing a recurring issue in the 2026 version where file copy operations fail with a "file not found" error, even though the file exists at the specified path. This problem happens consistently, and basic workarounds like verifying the path or manually copying the file don’t resolve it.

Please look into this as it’s affecting my workflow. Let me know if you need logs or more details.

[johnsonshiue]

Hi! Please make sure all the critical Windows updates, the latest graphics driver, and all the critical PC vendor updates are installed. Use Windows Disk Cleanup to remove cached files. Lastly, make sure the file path plus file name is less than 256 characters. When it exceeds 256 characters, the Inventor files can be corrupted on save.

Many thanks!