Assign material to selection does not work on certain layer

[alina_maria_agurida]

I am trying to use apply material on a table. It seems to work on my high poly layer, but not on my low poly one. When I use it on a box in the high layer, then move the box to the low layer, it turns back to gray. I also can no longer select an object by clicking it directly on the low layer. I am very new to 3ds Max and cannot figure out what I did wrong. 
If anyone has an idea, I would be really grateful. 

[RobH2]

There is something funky going on there. Hard to know. Can you upload the file and mention what version of Max?