Everything Greyed Out. SolidWorks 2018

Hey guys,

I'm working on my CSWPA. I downloaded the compression files from official website.

However, one of the files I opened, I literally cannot do anything.

Something I need to mention:

1. The instruction asked me to change some property and modify the model. I am supposed to do that. I checked the property of the file, it is not "read-only".

2. For now, only this file, other files in the same folder, are OK to edit.

3. I installed this software recently, I did even start using it yet. So it's impossible I changed some specific settings.

4. I have attached the file. You can try to download and edit it on your end.

Thanks in advance!!

SolidworksGeneral