Transparent Assembly

I am working with a large assembly. For some reason, the whole thing turned transparent. I can't seem figure out how to get it back to normal.

update...I just fixed it...not sure why this worked but I found this:

SPR 527554: Assembly components are displayed transparent.
Workaround: 1. Open the assembly 2. Press the spacebar on your keyboard 3. Select isometric from the menu 4. Control + Q 5. Save
Source: SPRs

Does anyone know why this worked?

SolidworksAssemblies