The Application.IgnoreRemoteRequests property corresponds to the “Ignore other applications that use Dynamic Data Exchange (DDE)” option in Microsoft Excel (it can be found in the File->Options->Advanced->General section).

When this option is turned ON, the running EXCEL.EXE instance becomes inaccessible for all the other applications (for example, the operating system will not use this instance to open Excel workbooks when a user double-clicks them in Windows Explorer).

JExcel turns ON this property to disable such access to the instances it is using, and then tries to restore the value of this property during proper shutdown. If JExcel shutdown was performed improperly or there was a Java crash, the value of this option may not be restored. As a result, Microsoft Excel may seem to be "broken", refusing to open any files on double-click.

In this case, it is recommended to check the state of this property through the Microsoft Excel UI and turn it OFF if it is enabled (this is the most common state of the property for the regular usage of Microsoft Excel).

There were a number of issues reported related to usage of this property in JExcel, and there is the -Dteamdev.jexcel.ignoreRemoteRequests=false VM argument for those users who wanted to avoid using this property in JExcel at all.