We bought the CC, iClone & 3DXchange pipeline a couple of weeks ago.Since then, during the last couple of weeks, we were able to create near 150 characters and import related Skeletal Meshes into Unreal Engine without any problem, being all already set, prepared and tested to run animations in UE4.25 as it should happen.
Yet, since that friday, upon both updates of CC3.3 and UE4.25.2, the same process that we have used for the 150 characters is no longer working, causing severe crashes in UE4.25.2 at the point of damaging both skeletal meshes and MAPS in way of not being able to edit them again.
For this technical problem, we have shot proper screen recording in way of being properly analysed by your technicians and programmers...
You can confirm it on this 16 minutes video: https://vimeo.com/442114294  (includes the fbx setup that we have used for all previous 150 characters)...

As of the severe UE4 crash event happens everytime we use any of the new CC3 base plus characters, including CALEB which does not have hair.
Yet, could not be so weird if the problem is on the new AUTO SETUP for Unreal Engine, we believe.
You see, the problem is not exactly the existence on an error, but rather the verification that does not popup any specific error message at all.Just crashes the UE4 Editor.
Being a really serious error once that after any crash the related MAP scenario file not longer allowing to edit again. Losing all that data and hundreds of hours of work.

Hello!

We are unable to reproduce this issue on our side, but the version we are using is UE4.25.3, that might cause the difference.
May you submit this issue to Feedback Tracker, and attach an FBX file for us to verify?
https://www.reallusion.com/FeedBackTracker/

Thanks!

OK, we are updating to UE4.25.3... Meanwhile also in staff holidays.
So, will post here any further update.

Now it's confirmed, the reported crash error continue to occur everytime I use any CC3 Base PLUS avatar/character...
Yet, if using the transformed by selecting the CC3 normal base it works fine on Unreal Engine.
Happeing everytie I use a CC3 Base PLUS !!!

Again, this is a severe error once that crash the UE4 editor and does not allow to open the map level that was being used !

OK, finally I could figure it out the problem.
I still didn't solved yet on the project that I was working. But if creating a new project everything seems to work fine on UE4 and all characters are imported.

Yet, the issue is even more problematic and severe once that after crashing the UE4 editor all characters that were imported on that session are locked down and could not be open again, like happened with the map level.
So, the issues is surely on the CC Auto Setup for UE4. That was working fine for 150 characters using the previous version of the auto setup.
Concluding that the issue that started to crash the editor was because of the auto setup update for the new version using the same project.
Requiring after update to the last version to create a brand new project instead.

Try troubleshooting your issue.  Document where the breakdown occurs starting with the default CC3 Plus avatar being brought into 4.25.3.
This many users can attest to doing without issue, so see if that, at base default, is an issue.

If you mean troubleshoting as detection of errors by exclusion of parts, here's what I did found and the related steps...
1 - I've installed the plugin CC Auto Setup 1.04 for UE4 in one project where I could import near 150 characters from CC3
2 - Upon the release of CC3.3, in conformity with reallusion instructions, I've updated the plugin CC Auto Setup for the version 1.1 in the same UE4 project where I have all other characteres
3 - In result, if I try to import any CC3.3 Base Plus character, the UE4 editor crash and lock the Map level not allowing to access it again (as shown on the video and previous posts here)
4 - Yet, it allows to continue importing characters in the same project from CC3 Base via Transformer !
5 - But when importing any CC3.3 Base Plus it will crash the editor, lock the map level and lock also all previous CC3 base characters as well, being all irremediably not accessible
6 - Clearly, the problem is the cache data stored on the CC_Shaders folder in UE4 related with the CC Auto Setup plugin that have messed the files between version 1.04 and 1.1
7 - I've so installed a brand new project and the auto setup 1.1 and everything works fine both importing CC3 Base and Base Plus Characters
In conclusion, the problem was derived from the attempt on upgrading the plugin Auto Setup to the new version using a production project. What seems not advisable to do.

Okay, you criss-crossed different versions mid-stream
Unreal HATES stuff like that, it is very temperamental with things like changing the folder setup.
I do stuff like that too, that really sucks and is annoying, sorry you had to deal with that....

But yeah, starting with a new slate in 1.1 will avoid any importing quagmire with CC3+.
I think if you had stuck with just old-CC3, you could have continued, but you would not be able to import CC3+ into that production project. 

Hi everyone! 
 I am having an issue with UE4 aswell, I need to import them into a UE4 project in order to migrate them into UE5 without manually setting the characters up. here is my crash log, very similar.

 I'm using the newest release of CC3 and Unreal Engine 4.27 using auto setup 1.22.

When i import my latest character, i get this crash log. The character has got multiple layers of beard, whereas all previous characters didn't have that.

Is there a fix for this?
My UE4 project is a new empty project just with the Auto Setup plugin enabled and the CC_Shaders folder.