Locked Ambient and Diffuse channels
 
 
 

The 3ds Max FBX plug-in does not export 3ds Max Lock information from Ambient and Diffuse channels. If you define a texture in the Ambient channel when you import an FBX file into 3ds Max, the Ambient, and Diffuse channels become unlocked. To preserve the locked state of the channel, you must lock them after you import the scene.