Why am I getting this message when I try to save in FMB?

[FG28_Kodiak]

First if you use an actor like a truck you need a second waypoint, simple set one near the first or look into artillery they don't need a waypoint or into static object there also trucks you can use without need of a wp.

The building '0_bld' has unlinked hooks has to do with larger industrial buildings (these who use more than one part to finish), it's a bug we can nothing do against. Only solution is not to use them.

[major_setback]

OK, thanks a lot for your help.
I'll save my work regularly during the build to save this sort of thing happening.

[huninthesun]

In the current release there are now factory objects under Static (No country)/Building/Industrial - these look identical to the German factory buildings but they can be assembled on the map without the unlinked hooks error.