That error seems somewhat unrelated to the specific asset. Could you detail your debug steps in how you determined the fences were causing an issue? Which fence asset exactly (industrial, wooden, or metal)? When you say you did some ‘hacking of the editor’ and it revealed the source of the problem could you please explain this process?
What engine version are you currently using? The latest asset is version 4.8 and if you are using 4.9 or higher I know there are some depreciated nodes that must be replaced. This was my initial thought when I saw your post, but you mentioned that you didn’t do any debugging in the actual blueprint so I don’t think that can be the case then. By the sounds of it, it isn’t every fence but a couple in a lot of fencing that is causing the issue. Could you provide some screenshots and your debugging process so I can try to make sure we can resolve the issue you are having?
Thank you in advance!