MCX Unknown error in MCX

[Fischkopp]

Hi Arno and hi everyone on the forum, I could use some help with the error message described below.

I’ve been using MCX for quite a while now to create freeware scenes. Today, however, when I tried to import a DAE model, I received the following error message—one I’ve never seen before—and I’m not sure what to make of it. The message reads:

Error importing file: Unable to resolve library reference “ID496”

Unfortunately, I don’t know what the library reference ID496 is or how I could find out.
The model was built in SketchUp and then exported as a DAE file so I could edit it further in MCX and use it as a GLTF file for MSFS 2020 and 2024.

I’m using version v1.9.2026.0806-devrel

Best regards, Manfred

 

[GaryGB]

Hello:

Not Arno here, but based on past issues with MCX' implementation of the ASSIMP 3D model inter-conversion library code having occasional problems with Collada *.DAE files, I would first try exporting the 3D model from Sketchup as a Google *.KMZ file.

Other export formats are also available in Sketchup's default options, and yet others are available to be used via free plugin Ruby scripts.

I suspect MCX may import the *.KMZ 3D model in question without an error, assuming it does not have a serious internal 3D structural anomaly,

Which numeric / year version of Sketchup was the 3D model created in ?

GaryGB

 

[arno]

Would you be able to share the model with me so that I can test it? I suspect it is either something in the Assimp library or the DAE file has some invalid content.

 

[GaryGB]

Interesting to see Google AI updated itself since just this morning on this subject (search Google via this query string)

ASSIMP Error importing file: Unable to resolve library reference ID 496

GaryGB

 

[Fischkopp]

@GaryGB​

Hi Gary, thanks for your quick reply.

You're right—the MCX imports the model without any problems in KMZ format. However, this also textures the interior surfaces, which I didn't want in MSFS for performance reasons.

The model was created in SketchUp 2020.


@arno
Hi Arno, thanks to you, too, for your quick reply.
Yes, I can send you the model or a link to download it. It’s a very simple barracks building with no major special features. I’ll send you the download link via private message.

I’ve been working with MCX for years now, but I’ve never had a problem like this before. After the barracks building, I built a few bike shelters with transparent glass walls and was able to import them into MCX as DAE files without any problems. Very strange.


In MCX imported as KMZ file

 

[Fischkopp]

I’ve now started troubleshooting as well, exporting all groups and objects individually as DAE files and trying to import them into MCX. Except for one group, it worked without any problems for all of them.
The problem therefore seems to lie in one of the two long walls (see image). It must really be the wall itself, because I was able to open the windows, doors and lamps in MCX without any issues.

 

[Fischkopp]

OK, I recreated the wall in question, and now it's working perfectly. But I don't know what the exact problem was.

 

[arno]

Good to hear you fixed it. I will still take a look at the file you send me to check where the error comes from. I suspect SketchUp made an invalid file, but it would be better if Assimp ignored the missing reference instead of throwing an error.

 

[GaryGB]

@GaryGB​

Hi Gary, thanks for your quick reply.

You're right—the MCX imports the model without any problems in KMZ format. However, this also textures the interior surfaces, which I didn't want in MSFS for performance reasons.

Hi again:

IIRC, MCX has an Option to disable Material display on the Reverse Face of 3D models.

Try this query string in a Google search:

ModelConverterX MCX Material Editor remove double-sided

GaryGB

 

[arno]

Gary, the intend of the forum is to share knowledge and solutions, not to tell people how to use a search engine. So either post a solution, or don't reply to a thread.

@Fischkopp, what Gary probably points at is that you can check if unchecking the double sided attribute in the material helps.

 

[GaryGB]

Gary, the intend of the forum is to share knowledge and solutions, not to tell people how to use a search engine. So either post a solution, or don't reply to a thread.

@Fischkopp, what Gary probably points at is that you can check if unchecking the double sided attribute in the material helps.

My original post above (which I edited) would have involved links to original threads here discussing ongoing issues with anomalous results and errors thrown by ASSIMP when Collada DAE Sketchup 3D models are imported into MCX.

I can arrange to do that, or I can post an abbreviated version of that reply, by simply quoting what Dick had previously stated:

ModelConverterX can remove the double-sided option in the materials editor, I believe.

Dick

Dick is typically rather thorough, and I would typically assume he had tested something prior to an assertion in the forum.


Are you stating that you are not certain MCX can prevent display of Materials on (double-sided) interior Faces of 3D models ?


I certainly was not inferring the use of that Option in MCX would have an impact on ASSIMP throwing an error.


Manfred reminded us that the KMZ exporter in Sketchup defaults to use of double-sided Faces, and I posted a presumed fix.


As I see it now, use of KMZ imports is largely a convenience for FS2Kx 3D model import to MCX with geo-location info.

Because MSFS now keeps geo-location info in a separate BGL (which FS2Kx 'could' also do in 2-types of placement files), we now have to perform an additional amount of work to generate placement for glTF 3D models.

I hope we may eventually see a way to simplify this process if we import 3D models to MCX with intent to output MSFS projects.


But I think those who use Sketchup for MSFS may eventually see the benefit of first exporting to glTF 2.0 via plugin Ruby scripts.

I have had good results with glTF 2.0 format thus far, and although ASSIMP is used in some Sketchup plugins without the same error as MCX displays, MCX (to its credit) is able to import glTF without errors / issues associated with Collada DAE or KMZ files.

I would be glad to encourage that Sketchup users begin exploring the (free) options for glTF import / export in the future.


BTW: This forum otherwise encourages use of AI (unlike some websites which are now attempting to de-emphasize use of AI).

AFAIK, referring to a "query string" to yield results which can save a forum participant a lot of personal time and effort is not significantly distinct from discussions here that include query strings and other info on how to use AI for FS SDK related work.

The FSDEV Search tool (notice I did not use the term 'engine') IMHO, is limited and rarely meets the needs of queries.

When a Google search is performed at the option of a forum participant, they can find answers in a fast and efficient manner.


Google searches are not intended to discourage- or substitute for- FSDEV discussions or unique new replies in threads.


Is there a concern here that FSDEV forum users may be 'offended' by not receiving unique new replies in threads ?

Since its very beginning, FSDEV forum sees threads go unanswered entirely- or for inordinately long periods of time.

But that is true of any / all web discussion forums.


Is there a concern here that FSDEV forum participation may be adversely affected by encouraging Google searches ?


If so, FSDEV forum may benefit from a "major re-think" of what some may see as reasons for declining participation here.


Admonishing a respondent to a thread to not point an OP to info on how to solve a FS Development issue is curious.


Most of the truly meaningful info that a FSDEV inquiry seeks ends up being found right back here at FSDEV forums.

Google knows this, and that is why their "bots" munch through FSDEV forum regularly.

But I daresay use of AI to substitute for unique in-person FS Development related content yields very slow FSDEV access times, as IIUC, each AI 'engine' may attempt to scrape FSDEV to build a unique database of resources to answer the end-user query.


A "problem" with FSDEV forum inquirers is the time requirement (and motivation ?) to Search (...and hopefully) Find info.

As I see it, a minimally worded example on what might be found "quicker" via a Google search is a valid and helpful reply.


I believe all of us here would like to see FSDEV continue to survive and thrive; we may all have unique ideas to help with that.



Are you now developing a set of guidelines for AI-related content "you" want FSDEV forum participants to post / not post ?

If so, I shall look forward to seeing to a more detailed and pro-active disclosure of such content guidelines.

GaryGB

 

[arno]

My original post above (which I edited) would have involved links to original threads here discussing ongoing issues with anomalous results and errors thrown by ASSIMP when Collada DAE Sketchup 3D models are imported into MCX.

I can arrange to do that, or I can post an abbreviated version of that reply, by simply quoting what Dick had previously stated:

I was referring to your last post before mine, where you posted try this query in Google. That is not an helpful post. In line with the forum rules replies should add knowledge and information and just suggesting to search in a search engine is not useful (it might not even give the same results for everybody).

Posting all kind of links to other threads with Assimp errors is also not useful, unless these errors have exactly the same error message.

Are you stating that you are not certain MCX can prevent display of Materials on (double-sided) interior Faces of 3D models ?

I know that the double sided material property does control if a polygon is rendered double sided or not. But I am not sure if the KMZ file with the double sided wall has this property set or if it has two separate polygons for the outside and inside wall. So therefore the solution might not work.

Because MSFS now keeps geo-location info in a separate BGL (which FS2Kx 'could' also do in 2-types of placement files), we now have to perform an additional amount of work to generate placement for glTF 3D models.

No, if you import a KMZ file and export it to a MSFS scenery package ModelConverterX will take care of the XML file for the placement and the glTF with the model and that will indeed result in a package with two BGL files. But it does not give a lot of extra work.

AFAIK, referring to a "query string" to yield results which can save a forum participant a lot of personal time and effort is not significantly distinct from discussions here that include query strings and other info on how to use AI for FS SDK related work.

Like I stated in my previous reply and we stated to you before, the forum rules state that posting links to search engine results is not allowed, since that is not consistent for all users and also it does not add to the body of knowledge that we have here in the forum. So you need to post actual solutions or helpful suggestions that helps people to find the solution. Period.

Is there a concern here that FSDEV forum users may be 'offended' by not receiving unique new replies in threads ?

Since its very beginning, FSDEV forum sees threads go unanswered entirely- or for inordinately long periods of time.

No, if nobody knows the answer to a question posted in a thread or has a suggestion for an approach to find a solution, it is not a problem that threads do not get answers. That is much better than having answers that are not related to the question.

Are you now developing a set of guidelines for AI-related content "you" want FSDEV forum participants to post / not post ?

The forum rules state what we allow here:

Terms and rules

You must agree to these terms and rules before using the site.

fsdeveloper.com

This discussion is going too much off-topic now already with this long post. So short summary post actual answers and stick to the rules.

 

[GaryGB]

Many thanks for configuring MCX to process geo-location info from imported KMZ files for both FS2Kx and MSFS project export.


I shall look forward to seeing what you can advise us to do in MCX to disable double-sided KMZ Material display,


Thanks as well, for a heads-up that searches with the same query strings may later yield variable (or per user ?) results.

I should have considered that further when I saw initial query results above had subsequently been edited by Google.

It may prove to be a serious concern for any meaningful future use of A.I. if 'user-profiling' yields inconsistent query results


Previously at FSDEV I have posted links to my own prior replies IMHO containing answers that are "related to the question".


Does FSDEV object to posting links pointing to prior threads at FSDEV ...containing answers that are "related to the question" ?

If not, can we post links to URLs unique to the FSDEV forum system (and not a long 'metadata' URL from a search engine) ?


FYI: I find some such links to potentially pertinent prior threads via the FSDEV Search history per (1) user or (1) keyword.

IIUC, that is due to the FSDEV Search doing an "include all" fuzzy query, so all query string element 'hits' are in the result.

However, last time I checked, FSDEV Search does not allow a search by 3-character file extension; this may compel "Googling".


Is it possible to upgrade the FSDEV search features so we are less compelled to go "offsite" to find FS Development answers ?


Thanks again for all you do with your FS utilities, and to keep FSDEV up and running.

GaryGB

 

[arno]

Gary, posting link to other threads or posts on the forum, as long as they are on-topic is fine. So if there is another thread with exactly the same problem it is fine. But if you start posting a dozen of links to vaguely related threads it is not helpful and thus not OK.

 

[arno]

Back to the topic of this thread, I check if Assimp has any options to not throw an error on a missing reference, but that is not supported. So the conclusion is that when this error happens SketchUp exported an invalid COLLADA file and you need to modify the object to get rid of that error as @Fischkopp already did.