When you say you took a copy of the folder, do you mean the folder where NetBackup keeps the DRFile for the catalog backup?
I would guess, (and it is a guess based on the limited information so far). The DRFile is poiniting to a location for the catalog backup that was either:-
1) another folder on the rebuilt system, that no longer exists, and as such it can't find the image to restore...
2) it is a location on Advanced Disk or MSDP, and you have not re-configure that so NetBackup can't find it yet.
Please cut and paste the content of the DR file that you were looking to use to initiate the catalog recover.
Also confirm where you believe the original Catalog Backup policy was backing up to, and that the storage has been configured yet.
If it was TAPE, have you reconfigured the library and inventoried it?
If it was Basic Disk, does the same path/folder exist?
If it was to storage on another media server have you configured that media server so the master can talk to it?
If a backup was via a diskpool, then you will need to have re-configured and set up the diskpool again so you can complete the restore.
See the following link for more info on reconfig of diskpools and then doing a nbcatsyc to get the DRFile corrected...
https://www.veritas.com/support/en_US/article.100000915