When I load a subassembly everything in VAB locks

[JackBush]

Title says it. I can't zoom or move around, raise or lower the subassembly. Is there a trick?

Edited December 19, 2015 by JackBush

[JackBush]

No answers? No one must be experiencing this. 

[Pecan]

Right, I had to experiment a bit to work out how to describe it and I still don't think I can explain it...

Although a sub-assembly has its own 'root' part, it is assumed that it will become attached to the rest of whatever ship you are building and that ship, by definition, also has to have a root part.  In an empty VAB or SPH if you load a sub-assembly it's 'loose' and not counted as a whole ship and there is no root part.  In other words you have to attach a sub-assembly to something.  You can un-freeze everything by clicking any allowed part from the list of parts and putting it into the VAB/SPH.  That then becomes the root part for the ship and you can attach the sub-assembly to it.  If you just wanted the sub-assembly as a complete ship you can then use the re-root tool to select a part on the original sub-assembly and delete the command pod you put in as a placeholder root part.  What you can't do is just load a sub-assembly on its own.

I don't know what the technical reasons for this are but you can see the same 'locked' effect by ... loading or building a ship, detaching everything from the root and then deleting the root part.  Without one you, again, can't move the camera or select anything in the VAB/SPH scene, the only thing you can do is add a new root part from the list of parts and attach the floating section of the ship to it.

There is also a 'merge' option for complete ships from the 'load' list, but I haven't used that much so can't comment.  Usually I both 'save' ships, so I can start with them (as KSP sees them as complete ships) and store them as sub-assemblies (which it doesn't).  There is probably a better way of doing things ^^.