Unable to open *.DRL file in Altium

Solution Details

When creating NC Drill output from the Altium Designer PCB Editor, five files are created during this process. The following files are placed in a sub-folder (within the project folder) named 'Out'.

1. .DRL (an older, legacy binary NC Drill Data, no longer used).
2. .DRR (the ASCII NC Drill Report Data).
3. .LDP (the ASCII Layer Pairs Export File).
4. .TXT (the ASCII NC Drill file).
5. StatusReport.TXT (the ASCII report file).

The .DRL is a binary file which can not be viewed in Camtastic, and is only provided for legacy purposes, the .TXT file is the ASCII NC Drill file you are looking for.