PR: Floors not exporting

[thumDer]

Problem Description

Floors not exporting to IFC. As per the export settings all Floor categories are mapped to IfcSlab(Type), and their corresponding enums. We've tried both with and without "Type", with and without the enums. IfcSlab is enabled in the IFC Entities to Export dialog. That shouldn't matter though, because for every other category any invalid Ifc Class entry will make those elements export to IfcBuildingElementProxy, not just skip those.

We've found the following workarounds, but these are unacceptable in a production environment:

• All Floor categories are mapped to IfcBuildingElementProxy Unfortunately this will render the Export to IFC As, and IFC Predefined Type parameters ineffective. Whatever their values are all elements end up IfcBuildingElementProxy
• Export to IFC or Export Type to IFC to be set to Yes instead of Default manually for all types / instances

This is a very inconsistent behaviour. Some of our PCs work just fine, others have this issue. All of them have Revit 24.2.0.63 and IFC Exporter 24.2.0.49

We also had this issue before in Revit 2022, but only on one computer, but now with Revit 2024 it is much more common.

Since there are no logs about the export process we are stuck with troubleshooting.

Revit Version

2024.0.x

IFC for Revit Addon Version

24.x.x

Windows Version

11 22H2

[AngelVelezSosa]

Hello, sorry for your issues. This is not a generic issue (as evidenced by the fact that it works on some of your machines), so we would need access to your files to see if we can reproduce the problem. It doesn't (and in fact, we prefer if it isn't) have to e your entire model - it can just be one floor that by itself exports on some of your machines and not others. If you can't narrow it down that way, then sending a file and marking the problematic floor would at least help. You shouldn't send it here - send a link to my Autodesk address and I'll get it in our internal system.

[thumDer]

We tested the affected computers with a minimal empty model, that only has 2 rectangular floors modeled, and the issue persist. So I'm almost 100% sure that it isn't model related. It would be really good if we had some debug logs. We plan to do additional tests on multiple computers, and in multiple Revit versions, because one of the affected computers have the same issuen in both Revit 2022 and Revit 2023 with the most recent IFC Exporters.

We double checked the IFC Files, and it is not only the geometries that are missing, its the complete entity.

[AngelVelezSosa]

One thing to check - do you have export mapping files on these machines? It's possible that the ones on the affected machines are corrupt/bad in some way, telling the floors not to export.

[thumDer]

The export mappings are linked from a network location, and it is enforced in the Revit.ini, so this setting is the same for all computers.

[AngelVelezSosa]

And everyone is on the same language of Revit? That's an issue before Revit 2025 (or maybe Revit 2024.X). I don't really know what environment issues could force the floors not to export. But have you at least checked the settings on the "bad" computer?

[thumDer]

Yes, we all use en-us. The computers supposed to be the same, more or less. Branded Lenovos, with managed installations. I will have more info about the frequency and the specs on monday.

[AngelVelezSosa]

I can't imagine the spec would matter for not being to export 2 floors. Maybe there is some issue getting to the network location? There has to be something generically wrong with the "bad" machine, whatever it is.

[thumDer]

We did some investigation

We've created a test model in versions 2022, 2023, 2024, which had 3 floor instances, one had no per type override, one had IfcSlab.BASESLAB override and the last had IfcSlab.ROOF override The category mapping had IfcSlab for all Floor categories

from the 3 revit versions we exported 2 ifc files, using ifc2x3 and ifc4 versions, with the default configs

out of 7 computers only one could export the elements, for all the 6 ifc models, 1 exported elements only from revit 2023, the other 5 computers exported empty ifc files

All computers had the same ifc exporter versions

The only workaround that worked, is to set the Export Type to IFC parameter to Yes instead of Default for all the Floor types.

This seems to be a critical bug, that affects most of our users.

[thumDer]

I've also found a very similar issue on the forums: https://forums.autodesk.com/t5/revit-architecture-forum/rvt23-ifc-export-problem-slab-site/td-p/12136390 What got me thinking is I assume the user posted that issue is also hungarian from his name, and however all of our Revit installs are en-us, the host OS (Win 11) is hungarian for everyone EXCEPT the only computer that managed to export correct IFCs. So, this is strange as hell, but it seems that this issue only affects hungarian localized WINDOWS environments?!

[AngelVelezSosa]

I still suggest you go through proper Autodesk support for this. They may have better resources for trying to figure out why it sometimes works. There clearly has to be something different in the steps otherwise it would never work.

[thumDer]

First I will try to change the system language settings on one of the computers to see if it makes any difference. Honestly, I don't really have positive experience with the support, especially in technically complicated issues, but can't hurt. Can you share some additional insights about the issues regarding the Revit language differences?

[AngelVelezSosa]

The only "old" issue was the export mapping table (before Revit 2025) could be in the wrong language, and export nothing. There could also be issues with encoding, ANSI vs UTF-8, but again those should either all work or all not. If the computers had different add-ins installed, that could be a thing. There has to be something different.

[thumDer]

After testing my hypothesis, I can confirm with 100% certainty that the windows language setting is the cause of this particular problem. After changing the system language, the export succeeds on a computer where it failed before the language change. Nothing was changed except the language.

Here are the before & after exported IFCs: https://inexkft-my.sharepoint.com/:f:/g/personal/tamas_deri_in-ex_hu/ErjnAYsPr-VDiNsWIHQuby0B1-uiqlWZbWAJ5yVN-5sXoA?e=hiTzMd

[AngelVelezSosa]

I can't access that sharepoint, but is the issue that one IFC file is very tiny (very little in it) and the other one is "complete"? And you are using a version of Revit before 2025? If so, then it may just be that you need an export mapping table for each system language, because everything is basically set not to export. Alternatively, if it is dependent on the language, I wonder if there are categories with characters other than a-z and A-Z that cause the encoding of the mapping file ot have issues.

[thumDer]

Sorry, I've just updated the link. The issue is one ifc is empty (has no building elements), while the other has all the floors from the Revit model. Our Revit is in English, so all our mapping files are in english, and have no other characters just the ones you mentioned. The encoding of the mapping file is UTF-16 LE. I don't expect from you to install hungarian language pack on your pc end get completely lost, so I can offer a call with screen sharing to demonstrate the issue, and try to troubleshoot it.

[batyitam]

I can confirm for other IFC 4 relate export issue (Ifc export as is onverruled to buildingelementproxy for example roof, slab, stair and some other random elements). Other elements exported normally. If I switch to english language (windows 10) the export works as expected. With some elements (shading, ladder exported as stair/userdefined) still exporting as proxy.