Large Assembly Fatal Error on save after iLogic runs in 2025

[shannon.lundrigan]

My client has a large assembly with iLogic rules that configure options from the top level, deleting components that are not required (rules at the top level trigger rules within parts and sub assemblies etc.)
The rules ran fine in 2023, now they have upgraded to 2025. They run a copy design on the top-level assembly, then run their configuration on the top level copy. After the rules run and the assembly updates, they try to save and get a Fatal Error. Then Inventor crashes without the ability to run a crash report.

We've tried migrating the files manually but now even if the program doesn't crash after running iLogic at the top level, the rules no longer trigger inside some components. The components that do not get their rules to fire, seem to be random, it's not all of them but it's different ones each time. 
Looking for any known migration bugs or fixes or things to try.
Running Inventor 2025.2.1, Vault Pro (2025)

[Curtis_Waguespack]

@shannon.lundrigan , there were serval things that have caused errors in existing rules in 2025. If you can provide an example of one of the rules someone might be able to spot the issue. Otherwise you might read through the posts at this link:

https://forums.autodesk.com/t5/forums/searchpage/tab/message?advanced=false&allow_punctuation=false&...

[JMGunnar]

Try too  remove 

remove all modelstate from sub assemblies 

this is the biggest  probelm in this type off soultions that's 

i never use  ilogic with modelstate

modelstate have different command too place too

Best Regards Johan G 

@shannon.lundrigan 

[bradeneuropeArthur]

Looks like a programming issue. Could you share the code. You can also do it via a private message. A known issue may be that inventor turned into NET 8...

[bradeneuropeArthur]

Using addins is also a step forward