Help! everything is grey and I can't copy and paste an object to another artworks

[Igor5E62]

When I open this file everything turns grey and I can't see an object at all. 
The object is still there, I can see it when i go to outline mode.
Somebody, please, tell me whats going on?

Also, when I first opened this file it said something about honering 9-slice scaling of symbols. maybe it helps

[pv_alm]

Hi,

try by copy paste that object into a new document

[Igor5E62]

Hi, it didn't help. The new document turned grey as well

[Monika Gause · Accepted solution]

There are a couple of PNGs in that file, any chance that they cover the object?

What does the layers panel tell you about the file?

The symbols error just tells you that this is a very old file. Or a file created by some other software that can only write AI version 8 files.

So what is the history of that file? Where did you get it from?

[Igor5E62]

Hi! By unchecking some layers everything came back to normal, so thank u very much!

This file I got in stock and it is possible that this bug happened because of the newer version of illustrator that I just reinstalled. Still a mystery, but at least I can deal with it.
Thank u again and have a nice day!