FS2004 "At least one sub material slot is unused"

Hi guys, it's been a little while since I opened Gmax, but something lately caught my eye in a scenery I developed and I wanted to make a change.

Since it's been a while, I forgot some techniques, one in particular is the remedy for this export error.

"At least one sub material slot is unused"

I know it relates to the materials, and I know some numbers are out of sequence, but I can't recall what I need to do. Can someone offer me a sequence of steps to resolve this? I greatly appreciate it.

Doug Smith


Resource contributor
Open the Multimaterial that is giving the error.

Find which slot is empty.

1. If it is the 'last' one you are in luck ... just delete it.

2. If it is not, you may choose just to put a material in there anyway, so you don't have to rearrange the material ID's in the model.
The compiled model should have no extra bits, if that 'submaterial' is not applied anywhere.

3. If you are fussy about neat material editors:

Select by ID using the last MaterialID on the list.
Change those ID's to the number corresponding to the 'empty' slot, for all bits of geometry that use the multimaterial.
Once you have done this, drag the last Material in the Multimaterial into that empty slot.
You may now delete the last Material Slot from the multimaterial.

Personally, I'd favour option 2 over option 3.