FSDS3 scenery problem

[Hurricane]

I've created various buildings in FSDS3 and each one will export fine on its own into flight sim but when I merge them into one file to export them it comes up with an error (see attachment). Anybody got any ideas why? :banghead:

[scruffyduck]

I can't tell you why but an assertion failure is when something happens in a program which should not happen. In this case it seems to be MakeMdl. It would need the authors of that program to identify the cause. However it may well be that MakeMdl will only accept one source file at a time.

[Hurricane]

Thanks, Its strange as last night I tried merging two other fliles not related to this scenery and it worked fine. So it looks like I just need to start again from scratch with merging them