The AutoFitWidth functionality does not take into account the filtering button.

Formula evaluation causes an endless loop when importing a specific file

The vertical grid lines are not visible in a scatter chart. The grid lines are visible when opened in Excel.

 

The formula when adding a number to date is not calculated correctly. 

The content of some rows which contain new lines can be clipped when a fixed-width column is wrapped.

This can be observed in the following images.

Before the export:

After the export:

Exception when rounding a decimal value in a formula with a lot of precision numbers

An exception is thrown when importing a document containing custom number formats with date or time part and empty sections.

The full data for the images is not copied and they are missing in the target worksheet.

The XlsFormatProvider currently doesn't support charts and skips them while importing or exporting a document.

The import process takes much time when the formatting of the cells needs to be resolved. 

If there are cells in the column with wrapped content, containing text with more than one word, and other cells with smaller content, the auto-fitting does not respect the width of the wrapped cell and sets the column width to the width of the other smaller cells.

Formulas referring to cells containing cell references are not recalculated if the imported document containing cached formula values.

Importing a document containing [hh]:mm number format causes an ArgumentException.

When importing a document with encrypted records a NotImplementedException is thrown: System.NotImplementedException: "Implement it based on poi 4.2 in the future".

When exporting to PDF, the hidden sheets should not be included in the layout. Or, at least, there should be an option whether to skip them or not.

Add support for Excel 5.0/95 Workbooks.

From the OOXML Specification: A comment is a rich-text note that is attached to and associated with a cell, separate from other cell content.

In Office 365 there are two types of comments:

• Comments/Notes
• Threaded Comments

This item applies to Comments/Notes only.

For Threaded Comments, please follow: SpreadProcessing: Comments (Threaded Comments)

When importing a document containing a formula with an invalid reference an exception is thrown: FormulaParseException: 'Unused input [A1] after attempting to parse the formula [#REF!A1]'

When importing a document containing a destination that does not refer to a formula an exception is thrown: System.NullReferenceException: 'Object reference not set to an instance of an object.'

Exporting sheet properties corrupts the file and it cannot be opened in Excel.

In the latest version we export: 

<sheetPr>
<pageSetUpPr fitToPage="true" />
<tabColor rgb="FF92D050" />
</sheetPr>

Excel cannot read this and tries to recover the file unsuccessfully. This works in R3 2020.