So I have generated a rather large worldspace complete with regions etc. It is completed and has worked for quite some time. I stopped work on it, and then picked it back up a few weeks ago. This time around my Trees which had been working fine, no longer load in the current cell, even though in the CS they are fine and The LOD billboards display correctly. IT isn't any specific tree...so it isn't a missing spt file. I have been banging my head against the problem for some time and can't find a solution. I've tried load orders, move to master, and double checked all my settings and CS stuff three or four times. Currently this mod is the only one active in my load order. If anyone here knows the solution I would greatly appreciate the help.

Indefiance

Edit for solution:
Well I thought I would post a solution for others who may encounter the error. I had my .esm and was working on the .esp. I recombined them with Gecko, converted that to an .esp and then re-split that so as to clear the .esp of any VWD flags...which apparently causes the error. This process finally solved the problem.