Just to clarify - this did not occur with an earlier version of Dev branch (haven't played for about a month) with same mods. Only just started happening after update.

There are no addons activated at all. I cannot activate or disable mods using Arma 3 because attempting to access the menu to do this freezes the game. I have removed all the mods from the Arma 3 root folder in order to disable them as I originally thought it might have been one of them misbehaving. I am subsequently unable to reactivate them and so they remain disabled.

Discovered the problem - for some reason the mod "Community Base Addons" was interfering. Disabled mod and now it works. Thanks for your time though :)

That was the first thing I tried. If the files were indeed missing, surely I would be unable to play the mission at all?

I'm getting the same error for other missions too.

I'm experiencing the same issue. I've verified my game cache which returned no problems.

Attempting to spawn any assets using the editor results in this error and is unplayable. Attempting to load showcases results in this error but is playable. Main menu results in this error.

Development Build 1.07.113178.
Issue arising since update today (4th Dec 2013)

Additionally: playing Scenarios and Campaign Missions return this error but are playable. The error appears to only cause unplayability for the editor.

When I use the "unload" waypoint it automatically ejects any passengers. I've never used the "get out" waypoint as that causes the pilot and crew to exit the vehicle.

This is with the invisible helipad.

This is with the completion and placement radii both set to "0"

I've managed to reproduce this too. It's not just civilian vehicles. Also, on the eastern bridge, heading north-south, vehicles drive into a wall, then over it and crash into the children's slide. Presumably the bridges are classed as solid objects rather than roads?

@SharkBaztard - I do always use both the textured and untextured versions of the editor, but thanks