drawing is on the file can't turn layer on or something

I received a file via mail from a client. parts of the drawing were not visible. searched settings for hours and finally got layer or something turned on and it appeared. I thought I saved the changes but it didn't save. I need to access the file and can not remember what I did to make it appear. all of the layers are turned on. Does anybody have an idea what is disabled or off?

You might check if those objects are not hidden, look at the bottom right corner of the screen and see if there is a little red bulb, if it is yellow then this is not the case, if it's red, mouse-click it and choose "end object isolation"

I don't have the bulb. I have an old version. Do you know how I can access that feature without the bulb?

Hmm, not sure if your version had this feature then, but you can try typing AecUnIsolateObjects and press enter, see if that helps.

Are there xrefs involved? If so, check VISRETAIN.

Are these areas of the dwg blocks with nested layers? Is layer 0 turned off or frozen?

layer 0 is not turned off or frozen. VISRETAIN did not work. It's crazy I know it's there I made it appear before and actually set up a layout and printed it, I just can't see it or select it. All I can remember is that it seemed like they changed settings on colors on the plot style manager or something. It is something simple like that.

Could they be PROXY objects? What software was the dwg created in?

Can you search for object enablers?