I created a report in OBIEE12c. But I dint find and .xdo, .xdm, xdo.cfg .... file in any of the folders. In OBIEE 11g they use to be there in some repository directory. Where and how OBIEE 12c stores catalog objects/repositories.
The method of copying between environments may be causing your problem.
Best practice is to navigate to the xmlpserver (BI Publisher interface) and Download/Upload within there in the source/destination environments, respectively. (BIP uses "Download"/"Upload" rather than "Archive"/"Unarchive" as used in the OBIEE general interface.)
Your URL should look like this:
http://{Host}:{Port}/xmlpserver/servlet/catalog
Not this, as in OBIEE interface:
http://{Host}:{Port}/analytics/saw.dll?catalog
This is how you get the Download/Upload options in the "More" menu next to your BIP catalog objects.
Alternatively, this could be due to a problem in the Catalog. Use BI Catalog Manager to help you investigate.
Lastly, you need to make sure that you've checked the permissions to the object in both environments.