Invalid Cell Value

```
What steps will reproduce the problem?
1.Create Workbook from file
2.
3.

What is the expected output? What do you see instead?
Create workbook in same format. Invalid cell value.

What version of the product are you using? On what operating system?

1.0.0.0/ Windows 8
Please provide any additional information below.

I want to include null value in worksheet
```

Original issue reported on code.google.com by `eldhoabe...@gmail.com` on 24 Oct 2013 at 8:21

Attachments:
- [DataEntry.xlsx](https://storage.googleapis.com/google-code-attachments/excellibrary/issue-153/comment-0/DataEntry.xlsx)

Start by opening the attached DataEntry.xlsx and reproducing the invalid-cell-value error with the reported 1.0.0.0 build on Windows 8. Then trace the workbook import path for the null worksheet value; done means the file loads without the error and retains the intended null value.

Written by the indexing model from the issue text.