# Release Notes for Version 12.45.20191.0

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## Content

This set of release notes includes resolved issues and version details.

## Resolved Issues

The following issues have been resolved since the last release.

* The ISBLANK formula now works correctly and null and String.Empty will be treated as blank. [269996]
* Now, the InvalidOperationException is thrown when a user tries to set the corner header cell text (the text in the top-left corner cell) while working with the spreadsheets. [269571]
* In the formula cell, the value is now calculated accurately without any issues and the result obtained after the calculation is correct. [272251]
* Now, the Excel files load properly while executing the import operation. [272147]

## File Versions

Spread WPF installs the following file versions on your system. See [Installed Files](/spreadnet/docs/latest/readme/installedfiles/installfilesWPF) for the exact location of these files.

| **File** | **Version** |
| ---- | ------- |
| GrapeCity.SpreadSheet.Design.dll | 12.45.20191.0 |
| GrapeCity.SpreadSheet.VSDesign.dll | 12.45.20191.0 |
| GrapeCity.WPF.CalcEngine.dll | 12.45.20191.0 |
| GrapeCity.WPF.Excel.dll | 12.45.20191.0 |
| GrapeCity.WPF.PDF.dll | 12.45.20191.0 |
| GrapeCity.WPF.SpreadSheet.Data.dll | 12.45.20191.0 |
| GrapeCity.WPF.SpreadSheet.UI.dll | 12.45.20191.0 |
| GrapeCity.WPF.SpreadSheet.UI.VisualStudio.Design.dll | 12.45.20191.0 |
| ICSharpCode.WPF.SharpZipLib.dll | 0.86.0.518 |