Error codes
| qg_noErr | 0 | No error |
| qg_paramErr | -50 | One of the parameters is illegal |
| qg_memFullErr | -108 | Out of memory |
| qg_demoExpiredErr | -29001 | The demo version has timed out |
| qg_CellIndexErr | -29105 | Cell index is out of range |
| qg_InternalIndexErr | -29201 | Drag and drop signature indexing error |