| ERROR | cannot perform string operation on an unopened file |
| CAUSE | The file is not open for the required operation to be performed. |
| ACTION | Check that the current operation is preceded by a successful file open operation. |
| ERROR | cannot perform string operation on an unopened file |
| CAUSE | The file is not open for the required operation to be performed. |
| ACTION | Check that the current operation is preceded by a successful file open operation. |