| IGR_E_OPEN_ERROR | 1 | Open error |
| IGR_E_WRONG_TYPE | 2 | Attempt to open file with wrong type |
| IGR_E_IN_USE | 3 | File is locked |
| IGR_E_NOT_READABLE | 4 | File is not readable |
| IGR_E_PASSWORD | 5 | File is encrypted |
| IGR_E_NOT_FOUND | 10 | File not found |
| IGR_E_WRITE_ERROR | 11 | Unable to write file |
| IGR_E_NOT_VALID_FOR_THIS_CLASS | 12 | Operation is not valid for this type of object |
| IGR_E_ERROR | 13 | General error |
| IGR_E_INVALID_HANDLE | 14 | Invalid handle |
| IGR_E_INVALID_POINTER | 15 | Invalid pointer |
| IGR_E_INVALID_PARAMETER | 16 | Invalid parameter |
| IGR_E_FILE_CORRUPT | 17 | Corrupt file |
| IGR_E_OUT_OF_MEMORY | 20 | Out of memory |
| IGR_E_BAD_ERROR | 21 | Bad error |
| IGR_E_WRONG_THREAD | 22 | Method called from wrong thread |
| IGR_E_TOO_MANY_HANDLES | 23 | Too many open handles |
| IGR_E_FONTS_NOT_FOUND | 24 | Fonts not found |
| IGR_E_VERSION_MISMATCH | 25 | Version mismatch |
| IGR_E_ACTION_NOT_SUPPORTED | 26 | Action not supported |
| IGR_CANCELLED | 27 | Operation has been cancelled |