Error codes
| qd_noErr | 0 | No error |
| qd_paramErr | -50 | Parameter error |
| qd_memFullErr | -108 | Out of memory |
| qd_fnfErr | -43 | File not found |
| qd_nsvErr | -35 | No such volume |
| qd_dskFullErr | -34 | Disk is full |
| qd_dupFNErr | -48 | Duplicate file name |
| qd_dirNFErr | -120 | Directory not found |
| qd_demoExpiredErr | -29001 | The demo version has timed out |
| qd_licenseExpiredErr | -29002 | The time-limited license has expired (obsolete) |